Fix some doc warnings (#12961)

# Objective

- Fix some doc warnings 
- Add doc-scrape-examples to all examples

Moved from #12692 

I run `cargo +nightly doc --workspace --all-features --no-deps
-Zunstable-options -Zrustdoc-scrape-examples`

<details>

```
warning: public documentation for `GzAssetLoaderError` links to private item `GzAssetLoader`
  --> examples/asset/asset_decompression.rs:24:47
   |
24 | /// Possible errors that can be produced by [`GzAssetLoader`]
   |                                               ^^^^^^^^^^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`
   = note: `#[warn(rustdoc::private_intra_doc_links)]` on by default

warning: `bevy` (example "asset_decompression") generated 1 warning
warning: unresolved link to `shape::Quad`
 --> examples/2d/mesh2d.rs:3:15
  |
3 | //! [`Quad`]: shape::Quad
  |               ^^^^^^^^^^^ no item named `shape` in scope
  |
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "mesh2d") generated 1 warning
warning: unresolved link to `WorldQuery`
 --> examples/ecs/custom_query_param.rs:1:49
  |
1 | //! This example illustrates the usage of the [`WorldQuery`] derive macro, which allows
  |                                                 ^^^^^^^^^^ no item named `WorldQuery` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "custom_query_param") generated 1 warning
warning: unresolved link to `shape::Quad`
 --> examples/2d/mesh2d_vertex_color_texture.rs:4:15
  |
4 | //! [`Quad`]: shape::Quad
  |               ^^^^^^^^^^^ no item named `shape` in scope
  |
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `bevy` (example "mesh2d_vertex_color_texture") generated 1 warning
warning: public documentation for `TextPlugin` links to private item `CoolText`
  --> examples/asset/processing/asset_processing.rs:48:9
   |
48 | /// * [`CoolText`]: a custom RON text format that supports dependencies and embedded dependencies
   |         ^^^^^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`
   = note: `#[warn(rustdoc::private_intra_doc_links)]` on by default

warning: public documentation for `TextPlugin` links to private item `Text`
  --> examples/asset/processing/asset_processing.rs:49:9
   |
49 | /// * [`Text`]: a "normal" plain text file
   |         ^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`

warning: public documentation for `TextPlugin` links to private item `CoolText`
  --> examples/asset/processing/asset_processing.rs:51:57
   |
51 | /// It also defines an asset processor that will load [`CoolText`], resolve embedded dependenc...
   |                                                         ^^^^^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`

warning: `bevy` (example "asset_processing") generated 3 warnings
warning: public documentation for `CustomAssetLoaderError` links to private item `CustomAssetLoader`
  --> examples/asset/custom_asset.rs:20:47
   |
20 | /// Possible errors that can be produced by [`CustomAssetLoader`]
   |                                               ^^^^^^^^^^^^^^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`
   = note: `#[warn(rustdoc::private_intra_doc_links)]` on by default

warning: public documentation for `BlobAssetLoaderError` links to private item `CustomAssetLoader`
  --> examples/asset/custom_asset.rs:61:47
   |
61 | /// Possible errors that can be produced by [`CustomAssetLoader`]
   |                                               ^^^^^^^^^^^^^^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`
```

```
warning: `bevy` (example "mesh2d") generated 1 warning
warning: public documentation for `log_layers_ecs` links to private item `update_subscriber`
 --> examples/app/log_layers_ecs.rs:6:18
  |
6 | //! Inside the [`update_subscriber`] function we will create a [`mpsc::Sender`] and a [`mpsc::R...
  |                  ^^^^^^^^^^^^^^^^^ this item is private
  |
  = note: this link will resolve properly if you pass `--document-private-items`
  = note: `#[warn(rustdoc::private_intra_doc_links)]` on by default

warning: unresolved link to `AdvancedLayer`
 --> examples/app/log_layers_ecs.rs:7:72
  |
7 | ... will go into the [`AdvancedLayer`] and the [`Receiver`](mpsc::Receiver) will
  |                        ^^^^^^^^^^^^^ no item named `AdvancedLayer` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: unresolved link to `LogEvents`
 --> examples/app/log_layers_ecs.rs:8:42
  |
8 | //! go into a non-send resource called [`LogEvents`] (It has to be non-send because [`Receiver`...
  |                                          ^^^^^^^^^ no item named `LogEvents` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

warning: public documentation for `log_layers_ecs` links to private item `transfer_log_events`
 --> examples/app/log_layers_ecs.rs:9:30
  |
9 | //! From there we will use [`transfer_log_events`] to transfer log events from [`LogEvents`] to...
  |                              ^^^^^^^^^^^^^^^^^^^ this item is private
  |
  = note: this link will resolve properly if you pass `--document-private-items`

warning: unresolved link to `LogEvents`
 --> examples/app/log_layers_ecs.rs:9:82
  |
9 | ...nsfer log events from [`LogEvents`] to an ECS event called [`LogEvent`].
  |                            ^^^^^^^^^ no item named `LogEvents` in scope
  |
  = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

warning: public documentation for `log_layers_ecs` links to private item `LogEvent`
 --> examples/app/log_layers_ecs.rs:9:119
  |
9 | ...nts`] to an ECS event called [`LogEvent`].
  |                                   ^^^^^^^^ this item is private
  |
  = note: this link will resolve properly if you pass `--document-private-items`

warning: public documentation for `log_layers_ecs` links to private item `LogEvent`
  --> examples/app/log_layers_ecs.rs:11:49
   |
11 | //! Finally, after all that we can access the [`LogEvent`] event from our systems and use it.
   |                                                 ^^^^^^^^ this item is private
   |
   = note: this link will resolve properly if you pass `--document-private-items`
```

<details/>

Cargo.toml

@@ -380,6 +380,7 @@ wasm = true
 [[example]]
 name = "2d_viewport_to_world"
 path = "examples/2d/2d_viewport_to_world.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.2d_viewport_to_world]
 name = "2D Viewport To World"
@@ -489,6 +490,7 @@ wasm = true
 [[example]]
 name = "sprite_tile"
 path = "examples/2d/sprite_tile.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.sprite_tile]
 name = "Sprite Tile"
@@ -499,6 +501,7 @@ wasm = true
 [[example]]
 name = "sprite_slice"
 path = "examples/2d/sprite_slice.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.sprite_slice]
 name = "Sprite Slice"
@@ -542,6 +545,7 @@ wasm = true
 [[example]]
 name = "pixel_grid_snap"
 path = "examples/2d/pixel_grid_snap.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.pixel_grid_snap]
 name = "Pixel Grid Snapping"
@@ -729,6 +733,7 @@ wasm = true
 [[example]]
 name = "deferred_rendering"
 path = "examples/3d/deferred_rendering.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.deferred_rendering]
 name = "Deferred Rendering"
@@ -893,6 +898,7 @@ wasm = true
 [[example]]
 name = "transmission"
 path = "examples/3d/transmission.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.transmission]
 name = "Transmission"
@@ -1145,6 +1151,7 @@ wasm = true
 [[example]]
 name = "log_layers"
 path = "examples/app/log_layers.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.log_layers]
 name = "Log layers"
@@ -1155,6 +1162,7 @@ wasm = false
 [[example]]
 name = "log_layers_ecs"
 path = "examples/app/log_layers_ecs.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.log_layers_ecs]
 name = "Advanced log layers"
@@ -1423,6 +1431,7 @@ wasm = true
 [[example]]
 name = "pitch"
 path = "examples/audio/pitch.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.pitch]
 name = "Pitch"
@@ -1595,6 +1604,7 @@ wasm = true
 [[example]]
 name = "one_shot_systems"
 path = "examples/ecs/one_shot_systems.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.one_shot_systems]
 name = "One Shot Systems"
@@ -1706,6 +1716,7 @@ wasm = false
 [[example]]
 name = "time"
 path = "examples/time/time.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.time]
 name = "Time handling"
@@ -1716,6 +1727,7 @@ wasm = false
 [[example]]
 name = "virtual_time"
 path = "examples/time/virtual_time.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.virtual_time]
 name = "Virtual time"
@@ -2072,6 +2084,7 @@ wasm = true
 [[example]]
 name = "extended_material"
 path = "examples/shader/extended_material.rs"
+doc-scrape-examples = true
 
 [package.metadata.example.extended_material]
 name = "Extended Material"

examples/2d/mesh2d.rs

@@ -1,6 +1,4 @@
-//! Shows how to render a polygonal [`Mesh`], generated from a [`Quad`] primitive, in a 2D scene.
-//!
-//! [`Quad`]: shape::Quad
+//! Shows how to render a polygonal [`Mesh`], generated from a [`Rectangle`] primitive, in a 2D scene.
 
 use bevy::{color::palettes::basic::PURPLE, prelude::*, sprite::MaterialMesh2dBundle};
 

examples/2d/mesh2d_vertex_color_texture.rs

@@ -1,7 +1,5 @@
-//! Shows how to render a polygonal [`Mesh`], generated from a [`Quad`] primitive, in a 2D scene.
+//! Shows how to render a polygonal [`Mesh`], generated from a [`Rectangle`] primitive, in a 2D scene.
 //! Adds a texture and colored vertices, giving per-vertex tinting.
-//!
-//! [`Quad`]: shape::Quad
 
 use bevy::{
     prelude::*,

examples/app/log_layers_ecs.rs

@@ -3,12 +3,12 @@
 //! The way we will do this is via a [`mpsc`] channel. [`mpsc`] channels allow 2 unrelated
 //! parts of the program to communicate (in this case, [`Layer`]s and Bevy's ECS).
 //!
-//! Inside the [`update_subscriber`] function we will create a [`mpsc::Sender`] and a [`mpsc::Receiver`] from a
-//! [`mpsc::channel`]. The [`Sender`](mpsc::Sender) will go into the [`AdvancedLayer`] and the [`Receiver`](mpsc::Receiver) will
-//! go into a non-send resource called [`LogEvents`] (It has to be non-send because [`Receiver`](mpsc::Receiver) is [`!Sync`](Sync)).
-//! From there we will use [`transfer_log_events`] to transfer log events from [`LogEvents`] to an ECS event called [`LogEvent`].
+//! Inside the `update_subscriber` function we will create a [`mpsc::Sender`] and a [`mpsc::Receiver`] from a
+//! [`mpsc::channel`]. The [`Sender`](mpsc::Sender) will go into the `AdvancedLayer` and the [`Receiver`](mpsc::Receiver) will
+//! go into a non-send resource called `LogEvents` (It has to be non-send because [`Receiver`](mpsc::Receiver) is [`!Sync`](Sync)).
+//! From there we will use `transfer_log_events` to transfer log events from `LogEvents` to an ECS event called `LogEvent`.
 //!
-//! Finally, after all that we can access the [`LogEvent`] event from our systems and use it.
+//! Finally, after all that we can access the `LogEvent` event from our systems and use it.
 //! In this example we build a simple log viewer.
 
 use std::sync::mpsc;
@@ -32,7 +32,7 @@ struct LogEvent {
 #[derive(Deref, DerefMut)]
 struct CapturedLogEvents(mpsc::Receiver<LogEvent>);
 
-/// Transfers information from the [`LogEvents`] resource to [`Events<LogEvent>`](LogEvent).
+/// Transfers information from the `LogEvents` resource to [`Events<LogEvent>`](LogEvent).
 fn transfer_log_events(
     receiver: NonSend<CapturedLogEvents>,
     mut log_events: EventWriter<LogEvent>,

examples/asset/asset_decompression.rs

@@ -24,7 +24,7 @@ struct GzAssetLoader;
 /// Possible errors that can be produced by [`GzAssetLoader`]
 #[non_exhaustive]
 #[derive(Debug, Error)]
-pub enum GzAssetLoaderError {
+enum GzAssetLoaderError {
     /// An [IO](std::io) Error
     #[error("Could not load asset: {0}")]
     Io(#[from] std::io::Error),

examples/asset/custom_asset.rs

@@ -20,7 +20,7 @@ struct CustomAssetLoader;
 /// Possible errors that can be produced by [`CustomAssetLoader`]
 #[non_exhaustive]
 #[derive(Debug, Error)]
-pub enum CustomAssetLoaderError {
+enum CustomAssetLoaderError {
     /// An [IO](std::io) Error
     #[error("Could not load asset: {0}")]
     Io(#[from] std::io::Error),
@@ -58,10 +58,10 @@ struct Blob {
 #[derive(Default)]
 struct BlobAssetLoader;
 
-/// Possible errors that can be produced by [`CustomAssetLoader`]
+/// Possible errors that can be produced by [`BlobAssetLoader`]
 #[non_exhaustive]
 #[derive(Debug, Error)]
-pub enum BlobAssetLoaderError {
+enum BlobAssetLoaderError {
     /// An [IO](std::io) Error
     #[error("Could not load file: {0}")]
     Io(#[from] std::io::Error),

examples/asset/processing/asset_processing.rs

@@ -51,7 +51,7 @@ fn main() {
 /// It also defines an asset processor that will load [`CoolText`], resolve embedded dependencies, and write the resulting
 /// output to a "normal" plain text file. When the processed asset is loaded, it is loaded as a Text (plaintext) asset.
 /// This illustrates that when you process an asset, you can change its type! However you don't _need_ to change the type.
-pub struct TextPlugin;
+struct TextPlugin;
 
 impl Plugin for TextPlugin {
     fn build(&self, app: &mut App) {

examples/ecs/custom_query_param.rs

@@ -1,4 +1,4 @@
-//! This example illustrates the usage of the [`WorldQuery`] derive macro, which allows
+//! This example illustrates the usage of the [`QueryData`] derive macro, which allows
 //! defining custom query and filter types.
 //!
 //! While regular tuple queries work great in most of simple scenarios, using custom queries
@@ -10,7 +10,7 @@
 //! - Named structs enable the composition pattern, that makes query types easier to re-use.
 //! - You can bypass the limit of 15 components that exists for query tuples.
 //!
-//! For more details on the `WorldQuery` derive macro, see the trait documentation.
+//! For more details on the [`QueryData`] derive macro, see the trait documentation.
 
 use bevy::{
     ecs::query::{QueryData, QueryFilter},
@@ -77,11 +77,11 @@ fn print_components_read_only(
     println!();
 }
 
-// If you are going to mutate the data in a query, you must mark it with the `mutable` attribute.
-// The `WorldQuery` derive macro will still create a read-only version, which will be have `ReadOnly`
-// suffix.
-// Note: if you want to use derive macros with read-only query variants, you need to pass them with
-// using the `derive` attribute.
+/// If you are going to mutate the data in a query, you must mark it with the `mutable` attribute.
+/// The [`QueryData`] derive macro will still create a read-only version, which will be have `ReadOnly`
+/// suffix.
+/// Note: if you want to use derive macros with read-only query variants, you need to pass them with
+/// using the `derive` attribute.
 #[derive(QueryData)]
 #[query_data(mutable, derive(Debug))]
 struct CustomQuery<T: Component + Debug, P: Component + Debug> {