docs: use intra-doc links instead of relative file paths (#2068)

## Motivation

#940, I guess. I kept running into the odd broken link in the docs and
eventually realized it's because a lot of stuff is reexported in parent
modules and so the file path based relative links couldn't possibly work
in all contexts. Looks like master already underwent this treatment but
I suspect this is easier than backporting.

## Solution

Intra-doc links seem pretty good.

I started with

```
        find -name \*.rs -exec sed -i -e '
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./\w\+\.\(\w\+\)\.html@\1super::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./\(\w\+\)/\w\+\.\(\w\+\)\.html@\1super::\2::\3@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./\.\./\w\+\.\(\w\+\)\.html@\1super::super::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./\.\./\(\w\+\)/\w\+\.\(\w\+\)\.html@\1super::super::\2::\3@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./\(\w\+\)/index\.html@\1super::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./index\.html@\1super@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\.\./\(\w\+\)/\?$@\1super::\2@;
    
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\./\w\+\.\(\w\+\)\.html@\1self::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\./\(\w\+\)/\w\+\.\(\w\+\)\.html@\1self::\2::\3@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\./\(\w\+\)/index\.html@\1self::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\./index\.html@\1self@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\./\(\w\+\)/\?$@\1self::\2@;
    
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\w\+\.\(\w\+\)\.html@\1self::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\(\w\+\)/\w\+\.\(\w\+\)\.html@\1self::\2::\3@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\(\w\+\)/index\.html@\1self::\2@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?index\.html@\1self@;
            s@\(//. \[[^]]*\]:\s\+\)[:"]\?\(\w\+\)/\?$@\1self::\2@;
    
            s@\(//. \[[^]]*\]:\s\+[A-Za-z_0-9:]\+\)#method\.\(\w\+\)@\1::\2@;
        ' {} +
```
and then removed redundant `self::`s when I realized you don't actually
need a `::` in the links, and fixed stuff up by hand as I ran into
errors from

```
x='--cfg docsrs --cfg tracing_unstable'; RUSTFLAGS=$x RUSTDOCFLAGS=$x cargo doc --all-features
```

I hope that's roughly how the docs are supposed to work.

I understand this is a relatively big unsolicited change in that it
touches a whole lot of files (definitely went further than I originally
intended), I'm happy to revise or split or reduce scope of this PR as
desired.

tracing-appender/src/lib.rs

@@ -10,7 +10,7 @@
 //! *Compiler support: [requires `rustc` 1.53+][msrv]*
 //!
 //! [msrv]: #supported-rust-versions
-//! [file_appender]: ./rolling/struct.RollingFileAppender.html
+//! [file_appender]: rolling::RollingFileAppender
 //! [tracing]: https://docs.rs/tracing/
 //!
 //! # Usage
@@ -88,12 +88,12 @@
 //!
 //! The [`non_blocking` module][non_blocking]'s documentation provides more detail on how to use `non_blocking`.
 //!
-//! [non_blocking]: ./non_blocking/index.html
+//! [non_blocking]: mod@non_blocking
 //! [write]: https://doc.rust-lang.org/std/io/trait.Write.html
-//! [guard]: ./non_blocking/struct.WorkerGuard.html
-//! [rolling]: ./rolling/index.html
+//! [guard]: non_blocking::WorkerGuard
+//! [rolling]: rolling
 //! [make_writer]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/fmt/trait.MakeWriter.html
-//! [rolling_struct]: ./rolling/struct.RollingFileAppender.html
+//! [rolling_struct]: rolling::RollingFileAppender
 //! [fmt_subscriber]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/fmt/struct.Subscriber.html
 //!
 //! ## Non-Blocking Rolling File Appender
@@ -166,7 +166,7 @@ pub(crate) mod sync;
 ///
 /// See the [`non_blocking` module's docs][non_blocking]'s for more details.
 ///
-/// [non_blocking]: ./non_blocking/index.html
+/// [non_blocking]: mod@non_blocking
 ///
 /// # Examples
 ///

tracing-appender/src/non_blocking.rs

@@ -19,7 +19,7 @@
 //! tracing_appender::non_blocking(std::io::stdout())
 //! # }
 //! ```
-//! [builder]: ./struct.NonBlockingBuilder.html#method.default
+//! [builder]: NonBlockingBuilder::default
 //!
 //! <br/> This function returns a tuple of `NonBlocking` and `WorkerGuard`.
 //! `NonBlocking` implements [`MakeWriter`] which integrates with `tracing_subscriber`.
@@ -33,7 +33,7 @@
 //!
 //! See [`WorkerGuard`][worker_guard] for examples of using the guard.
 //!
-//! [worker_guard]: ./struct.WorkerGuard.html
+//! [worker_guard]: WorkerGuard
 //!
 //! # Examples
 //!
@@ -65,7 +65,7 @@ use tracing_subscriber::fmt::MakeWriter;
 /// backpressure will be exerted on senders, causing them to block their
 /// respective threads until there is available capacity.
 ///
-/// [non-blocking]: ./struct.NonBlocking.html
+/// [non-blocking]: NonBlocking
 /// Recommended to be a power of 2.
 pub const DEFAULT_BUFFERED_LINES_LIMIT: usize = 128_000;
 
@@ -78,7 +78,7 @@ pub const DEFAULT_BUFFERED_LINES_LIMIT: usize = 128_000;
 /// terminates abruptly (such as through an uncaught `panic` or a `std::process::exit`), some spans
 /// or events may not be written.
 ///
-/// [`NonBlocking`]: ./struct.NonBlocking.html
+/// [`NonBlocking`]: NonBlocking
 /// Since spans/events and events recorded near a crash are often necessary for diagnosing the failure,
 /// `WorkerGuard` provides a mechanism to ensure that _all_ buffered logs are flushed to their output.
 /// `WorkerGuard` should be assigned in the `main` function or whatever the entrypoint of the program is.
@@ -145,8 +145,8 @@ impl NonBlocking {
     /// The returned `NonBlocking` writer will have the [default configuration][default] values.
     /// Other configurations can be specified using the [builder] interface.
     ///
-    /// [default]: ./struct.NonBlockingBuilder.html#method.default
-    /// [builder]: ./struct.NonBlockingBuilder.html
+    /// [default]: NonBlockingBuilder::default
+    /// [builder]: NonBlockingBuilder
     pub fn new<T: Write + Send + Sync + 'static>(writer: T) -> (NonBlocking, WorkerGuard) {
         NonBlockingBuilder::default().finish(writer)
     }
@@ -183,7 +183,7 @@ impl NonBlocking {
 
 /// A builder for [`NonBlocking`][non-blocking].
 ///
-/// [non-blocking]: ./struct.NonBlocking.html
+/// [non-blocking]: NonBlocking
 #[derive(Debug)]
 pub struct NonBlockingBuilder {
     buffered_lines_limit: usize,

tracing-appender/src/rolling.rs

@@ -1,6 +1,6 @@
 //! A rolling file appender.
 //!
-//! Creates a new log file at a fixed frequency as defined by [`Rotation`](struct.Rotation.html).
+//! Creates a new log file at a fixed frequency as defined by [`Rotation`][self::Rotation].
 //! Logs will be written to this file for the duration of the period and will automatically roll over
 //! to the newly created log file once the time period has elapsed.
 //!
@@ -17,10 +17,10 @@
 //! will be created daily
 //! - [`Rotation::never()`][never()]: This will result in log file located at `some_directory/log_file_name`
 //!
-//! [minutely]: fn.minutely.html
-//! [hourly]: fn.hourly.html
-//! [daily]: fn.daily.html
-//! [never]: fn.never.html
+//! [minutely]: minutely
+//! [hourly]: hourly
+//! [daily]: daily
+//! [never]: never
 //!
 //! # Examples
 //!
@@ -114,7 +114,7 @@ impl RollingFileAppender {
     /// Creates a new `RollingFileAppender`.
     ///
     /// A `RollingFileAppender` will have a fixed rotation whose frequency is
-    /// defined by [`Rotation`](struct.Rotation.html). The `directory` and
+    /// defined by [`Rotation`][self::Rotation]. The `directory` and
     /// `file_name_prefix` arguments determine the location and file name's _prefix_
     /// of the log file. `RollingFileAppender` will automatically append the current date
     /// and hour (UTC format) to the file name.
@@ -126,10 +126,10 @@ impl RollingFileAppender {
     /// - [`Rotation::daily()`][daily],
     /// - [`Rotation::never()`][never()]
     ///
-    /// [minutely]: fn.minutely.html
-    /// [hourly]: fn.hourly.html
-    /// [daily]: fn.daily.html
-    /// [never]: fn.never.html
+    /// [minutely]: minutely
+    /// [hourly]: hourly
+    /// [daily]: daily
+    /// [never]: never
     ///
     /// # Examples
     /// ```rust
@@ -284,7 +284,7 @@ pub fn hourly(
 /// a non-blocking, daily file appender.
 ///
 /// A `RollingFileAppender` has a fixed rotation whose frequency is
-/// defined by [`Rotation`](struct.Rotation.html). The `directory` and
+/// defined by [`Rotation`][self::Rotation]. The `directory` and
 /// `file_name_prefix` arguments determine the location and file name's _prefix_
 /// of the log file. `RollingFileAppender` automatically appends the current date in UTC.
 ///

tracing-attributes/src/lib.rs

@@ -36,7 +36,7 @@
 //!
 //! [`tracing`]: https://crates.io/crates/tracing
 //! [span]: https://docs.rs/tracing/latest/tracing/span/index.html
-//! [instrument]: attr.instrument.html
+//! [instrument]: macro@self::instrument
 //!
 //! ## Supported Rust Versions
 //!

tracing-core/src/callsite.rs

@@ -77,30 +77,29 @@ impl Registry {
 pub trait Callsite: Sync {
     /// Sets the [`Interest`] for this callsite.
     ///
-    /// [`Interest`]: ../subscriber/struct.Interest.html
+    /// [`Interest`]: super::subscriber::Interest
     fn set_interest(&self, interest: Interest);
 
     /// Returns the [metadata] associated with the callsite.
     ///
-    /// [metadata]: ../metadata/struct.Metadata.html
+    /// [metadata]: super::metadata::Metadata
     fn metadata(&self) -> &Metadata<'_>;
 }
 
 /// Uniquely identifies a [`Callsite`]
 ///
 /// Two `Identifier`s are equal if they both refer to the same callsite.
 ///
-/// [`Callsite`]: ../callsite/trait.Callsite.html
+/// [`Callsite`]: super::callsite::Callsite
 #[derive(Clone)]
 pub struct Identifier(
     /// **Warning**: The fields on this type are currently `pub` because it must
     /// be able to be constructed statically by macros. However, when `const
     /// fn`s are available on stable Rust, this will no longer be necessary.
     /// Thus, these fields are *not* considered stable public API, and they may
     /// change warning. Do not rely on any fields on `Identifier`. When
-    /// constructing new `Identifier`s, use the `identify_callsite!` macro or
-    /// the `Callsite::id` function instead.
-    // TODO: When `Callsite::id` is a const fn, this need no longer be `pub`.
+    /// constructing new `Identifier`s, use the `identify_callsite!` macro
+    /// instead.
     #[doc(hidden)]
     pub &'static dyn Callsite,
 );
@@ -119,11 +118,11 @@ pub struct Identifier(
 /// implementation at runtime, then it **must** call this function after that
 /// value changes, in order for the change to be reflected.
 ///
-/// [`max_level_hint`]: ../subscriber/trait.Subscriber.html#method.max_level_hint
-/// [`Callsite`]: ../callsite/trait.Callsite.html
-/// [`enabled`]: ../subscriber/trait.Subscriber.html#tymethod.enabled
-/// [`Interest::sometimes()`]: ../subscriber/struct.Interest.html#method.sometimes
-/// [`Subscriber`]: ../subscriber/trait.Subscriber.html
+/// [`max_level_hint`]: super::subscriber::Subscriber::max_level_hint
+/// [`Callsite`]: super::callsite::Callsite
+/// [`enabled`]: super::subscriber::Subscriber#tymethod.enabled
+/// [`Interest::sometimes()`]: super::subscriber::Interest::sometimes
+/// [`Subscriber`]: super::subscriber::Subscriber
 pub fn rebuild_interest_cache() {
     let mut registry = REGISTRY.lock().unwrap();
     registry.rebuild_interest();