Fix broken links in handbook

Fixes #15767

docs/contributors/managing-packages.md

@@ -1,8 +1,8 @@
 # Managing Packages
 
-This repository uses [lerna] to manage Gutenberg modules and publish them as packages to [npm]. This enforces certain steps in the workflow which are described in details in [packages](/packages/README.md) documentation.
+This repository uses [lerna] to manage Gutenberg modules and publish them as packages to [npm]. This enforces certain steps in the workflow which are described in details in [packages](https://github.com/WordPress/gutenberg/blob/master/packages/README.md) documentation.
 
-Maintaining dozens of npm packages is difficult—it can be tough to keep track of changes. That's why we use `CHANGELOG.md` files for each package to simplify the release process. As a contributor, you should add an entry to the aforementioned file each time you contribute adding production code as described in [Maintaining Changelogs](/packages/README.md#maintaining-changelogs) section.
+Maintaining dozens of npm packages is difficult—it can be tough to keep track of changes. That's why we use `CHANGELOG.md` files for each package to simplify the release process. As a contributor, you should add an entry to the aforementioned file each time you contribute adding production code as described in [Maintaining Changelogs](https://github.com/WordPress/gutenberg/blob/master/packages/README.md#maintaining-changelogs) section.
 
 [lerna]: https://lerna.js.org
 [npm]: https://www.npmjs.com/

docs/contributors/testing-overview.md

@@ -415,7 +415,7 @@ Related: https://chromedevtools.github.io/devtools-protocol/tot/Network#method-e
 
 ### Core Block Testing
 
-Every core block is required to have at least one set of fixture files for its main save function and one for each deprecation. These fixtures test the parsing and serialization of the block. See [the e2e tests fixtures readme](/packages/e2e-tests/fixtures/blocks/README.md) for more information and instructions.
+Every core block is required to have at least one set of fixture files for its main save function and one for each deprecation. These fixtures test the parsing and serialization of the block. See [the e2e tests fixtures readme](https://github.com/wordpress/gutenberg/blob/master/packages/e2e-tests/fixtures/blocks/README.md) for more information and instructions.
 
 ## PHP Testing
 

docs/designers-developers/designers/block-design.md

@@ -76,7 +76,7 @@ Avoid long, multi-line block names.
 
 Every block should include a description that clearly explains the block's function. The description will display in the Settings Sidebar.
 
-You can add a description by using the description attribute in the [registerBlockType function](/docs/designers-developers/developers/block-api/block-registration/). 
+You can add a description by using the description attribute in the [registerBlockType function](/docs/designers-developers/developers/block-api/block-registration.md). 
 
 Stick to a single imperative sentence with an action + subject format. Examples:
 

docs/designers-developers/developers/backward-compatibility/deprecations.md

@@ -241,11 +241,11 @@ For features included in the Gutenberg plugin, the deprecation policy is intende
 ## 3.0.0
 
  - `wp.blocks.registerCoreBlocks` function removed. Please use `wp.coreBlocks.registerCoreBlocks` instead.
- - Raw TinyMCE event handlers for `RichText` have been deprecated. Please use [documented props](/packages/editor/src/components/rich-text/README.md), ancestor event handler, or onSetup access to the internal editor instance event hub instead.
+ - Raw TinyMCE event handlers for `RichText` have been deprecated. Please use [documented props](https://github.com/WordPress/gutenberg/blob/v3.0.0/editor/components/rich-text/README.md), ancestor event handler, or onSetup access to the internal editor instance event hub instead.
 
 ## 2.8.0
 
- - `Original autocompleter interface in wp.components.Autocomplete` updated. Please use `latest autocompleter interface` instead. See [autocomplete](/packages/components/src/autocomplete/README.md) for more info.
+ - `Original autocompleter interface in wp.components.Autocomplete` updated. Please use `latest autocompleter interface` instead. See [autocomplete](https://github.com/WordPress/gutenberg/blob/v2.8.0/components/autocomplete/README.md) for more info.
  - `getInserterItems`: the `allowedBlockTypes` argument is now mandatory.
  - `getFrecentInserterItems`: the `allowedBlockTypes` argument is now mandatory.
 

docs/designers-developers/developers/block-api/block-deprecation.md

@@ -277,4 +277,4 @@ registerBlockType( 'gutenberg/block-with-deprecated-version', {
 
 In the example above we updated the block to use an inner Paragraph block with a title instead of a title attribute.
 
-*Above are example cases of block deprecation. For more, real-world examples, check for deprecations in the [core block library](/packages/block-library/src/README.md). Core blocks have been updated across releases and contain simple and complex deprecations.*
+*Above are example cases of block deprecation. For more, real-world examples, check for deprecations in the [core block library](https://github.com/WordPress/gutenberg/tree/master/packages/block-library/src). Core blocks have been updated across releases and contain simple and complex deprecations.*

docs/designers-developers/developers/block-api/block-templates.md

@@ -32,7 +32,7 @@ function myplugin_register_template() {
 add_action( 'init', 'myplugin_register_template' );
 ```
 
-The following example in JavaScript creates a new block using [InnerBlocks](/packages/block-editor/src/components/inner-blocks/README.md) and templates, when inserted creates a set of blocks based off the template.
+The following example in JavaScript creates a new block using [InnerBlocks](https://github.com/WordPress/gutenberg/blob/master/packages/block-editor/src/components/inner-blocks/README.md) and templates, when inserted creates a set of blocks based off the template.
 
 ```js
 const el = wp.element.createElement;

docs/designers-developers/developers/platform/README.md

@@ -5,7 +5,7 @@ The Gutenberg Project is not only building a better editor for WordPress, but al
 
 ## UI Components
 
-The [WordPress Components package](/docs/components/) contains a set of UI components you can use in your project. See the [WordPress Storybook site](https://wordpress.github.io/gutenberg/) for an interactive guide to the available components and settings.
+The [WordPress Components package](/packages/components/README.md) contains a set of UI components you can use in your project. See the [WordPress Storybook site](https://wordpress.github.io/gutenberg/) for an interactive guide to the available components and settings.
 
 Here is a quick example, how to use components in your project.
 

docs/designers-developers/developers/tutorials/block-tutorial/creating-dynamic-blocks.md

@@ -153,7 +153,7 @@ function gutenberg_examples_dynamic_render_callback( $block_attributes ) {
 
 ## Live rendering in the block editor
 
-Gutenberg 2.8 added the [`<ServerSideRender>`](/packages/components/src/server-side-render) block which enables rendering to take place on the server using PHP rather than in JavaScript. 
+Gutenberg 2.8 added the [`<ServerSideRender>`](/packages/server-side-render/README.md) block which enables rendering to take place on the server using PHP rather than in JavaScript. 
 
 *Server-side render is meant as a fallback; client-side rendering in JavaScript is always preferred (client rendering is faster and allows better editor manipulation).*
 

docs/designers-developers/developers/tutorials/block-tutorial/nested-blocks-inner-blocks.md

@@ -1,6 +1,6 @@
 # Nested Blocks: Using InnerBlocks
 
-You can create a single block that nests other blocks using the [InnerBlocks](/packages/block-editor/src/components/inner-blocks) component. This is used in the Columns block, Social Links block, or any block you want to contain other blocks.
+You can create a single block that nests other blocks using the [InnerBlocks](https://github.com/WordPress/gutenberg/tree/master/packages/block-editor/src/components/inner-blocks/README.md) component. This is used in the Columns block, Social Links block, or any block you want to contain other blocks.
 
 Note: A single block can only contain one `InnerBlock` component.
 
@@ -125,7 +125,7 @@ const MY_TEMPLATE = [
 ```
 {% end %}
 
-Use the `templateLock` property to lock down the template. Using `all` locks the template complete, no changes can be made. Using `insert` prevents additional blocks to be inserted, but existing blocks can be reorderd. See [templateLock documentation](/packages/block-editor/src/components/inner-blocks#templatelock) for additional information.
+Use the `templateLock` property to lock down the template. Using `all` locks the template complete, no changes can be made. Using `insert` prevents additional blocks to be inserted, but existing blocks can be reorderd. See [templateLock documentation](https://github.com/WordPress/gutenberg/tree/master/packages/block-editor/src/components/inner-blocks/README.md#templatelock) for additional information.
 
 ### Post Template
 

docs/designers-developers/developers/tutorials/format-api/2-toolbar-button.md

@@ -1,6 +1,6 @@
 # Add a Button to the Toolbar
 
-Now that the format is available, the next step is to surface it to the UI. You can make use of the [`RichTextToolbarButton`](/packages/editor/src/components/rich-text/README.md#RichTextToolbarButton) component to extend the format toolbar.
+Now that the format is available, the next step is to surface it to the UI. You can make use of the [`RichTextToolbarButton`](https://github.com/WordPress/gutenberg/tree/master/packages/block-editor/src/components/rich-text#richtexttoolbarbutton) component to extend the format toolbar.
 
 Paste this code in `my-custom-format.js`:
 

docs/designers-developers/developers/tutorials/metabox/meta-block-3-add.md

@@ -2,7 +2,7 @@
 
 With the meta field registered in the previous step, next you will create a new block used to display the field value to the user. See the [Block Tutorial](/docs/designers-developers/developers/tutorials/block-tutorial/readme.md) for a deeper understanding of creating custom blocks.
 
-For this block, you will use the TextControl component, which is similar to an HTML input text field. For additional components, check out the [components](/packages/components/src) and [editor](/packages/editor/src/components) packages repositories.
+For this block, you will use the TextControl component, which is similar to an HTML input text field. For additional components, check out the [Component Reference](/packages/components/README.md).
 
 The hook `useEntityProp` can be used by the blocks to get or change meta values.