docs(website): use .mdx extension for every docs (#8490)

website/versioned_docs/version-2.0.1/guides/docs/sidebar/autogenerated.mdx

@@ -33,7 +33,7 @@ module.exports = {
 };
 ```
 
-An `autogenerated` item is converted by Docusaurus to a **sidebar slice** (also discussed in [category shorthands](items.md#category-shorthand)): a list of items of type `doc` or `category`, so you can splice **multiple `autogenerated` items** from multiple directories, interleaving them with regular sidebar items, in one sidebar level.
+An `autogenerated` item is converted by Docusaurus to a **sidebar slice** (also discussed in [category shorthands](items.mdx#category-shorthand)): a list of items of type `doc` or `category`, so you can splice **multiple `autogenerated` items** from multiple directories, interleaving them with regular sidebar items, in one sidebar level.
 
 <details>
 <summary>A real-world example</summary>
@@ -171,7 +171,7 @@ A category index document is a document following one of those filename conventi
 - Named as `README` (case-insensitive): `docs/Guides/README.mdx`
 - Same name as parent folder: `docs/Guides/Guides.md`
 
-This is equivalent to using a category with a [doc link](items.md#category-doc-link):
+This is equivalent to using a category with a [doc link](items.mdx#category-doc-link):
 
 ```js title="sidebars.js"
 module.exports = {
@@ -370,7 +370,7 @@ customProps:
 
 :::info
 
-If the `link` is explicitly specified, Docusaurus will not apply any [default conventions](items.md#category-index-convention).
+If the `link` is explicitly specified, Docusaurus will not apply any [default conventions](items.mdx#category-index-convention).
 
 The doc links can be specified relatively, e.g. if the category is generated with the `guides` directory, `"link": {"type": "doc", "id": "intro"}` will be resolved to the ID `guides/intro`, only falling back to `intro` if a doc with the former ID doesn't exist.
 
@@ -414,8 +414,8 @@ By default, Docusaurus will **remove the number prefix** from the doc id, title,
 Updating a number prefix can be annoying, as it can require **updating multiple existing Markdown links**:
 
 ```diff title="docs/02-Tutorial Easy/01-First Part.md"
-- Check the [Tutorial End](../04-End.md);
-+ Check the [Tutorial End](../05-End.md);
+- Check the [Tutorial End](../04-End.mdx);
++ Check the [Tutorial End](../05-End.mdx);
 ```
 
 :::

website/versioned_docs/version-2.0.1/guides/docs/sidebar/index.mdx

@@ -42,7 +42,7 @@ import {useCurrentSidebarCategory} from '@docusaurus/theme-common';
 
 ## Default sidebar {#default-sidebar}
 
-If the `sidebarPath` is unspecified, Docusaurus [automatically generates a sidebar](autogenerated.md) for you, by using the filesystem structure of the `docs` folder:
+If the `sidebarPath` is unspecified, Docusaurus [automatically generates a sidebar](autogenerated.mdx) for you, by using the filesystem structure of the `docs` folder:
 
 ```js title="sidebars.js"
 module.exports = {
@@ -109,7 +109,7 @@ module.exports = {
 
 This is a sidebars file that exports one sidebar, called `mySidebar`. It has three top-level items: two categories and one external link. Within each category, there are a few doc links.
 
-A sidebars file can contain [**multiple sidebar objects**](multiple-sidebars.md), identified by their object keys.
+A sidebars file can contain [**multiple sidebar objects**](multiple-sidebars.mdx), identified by their object keys.
 
 ```ts
 type SidebarsFile = {

website/versioned_docs/version-2.0.1/guides/docs/sidebar/items.mdx

@@ -15,9 +15,9 @@ We have introduced three types of item types in the example in the previous sect
 - **[Doc](#sidebar-item-doc)**: link to a doc page, associating it with the sidebar
 - **[Link](#sidebar-item-link)**: link to any internal or external page
 - **[Category](#sidebar-item-category)**: creates a dropdown of sidebar items
-- **[Autogenerated](autogenerated.md)**: generate a sidebar slice automatically
+- **[Autogenerated](autogenerated.mdx)**: generate a sidebar slice automatically
 - **[HTML](#sidebar-item-html)**: renders pure HTML in the item's position
-- **[\*Ref](multiple-sidebars.md#sidebar-item-ref)**: link to a doc page, without making the item take part in navigation generation
+- **[\*Ref](multiple-sidebars.mdx#sidebar-item-ref)**: link to a doc page, without making the item take part in navigation generation
 
 ## Doc: link to a doc {#sidebar-item-doc}
 
@@ -230,7 +230,7 @@ With category links, clicking on a category can navigate you to another page.
 
 Use category links to introduce a category of documents.
 
-Autogenerated categories can use the [`_category_.yml`](./autogenerated.md#category-item-metadata) file to declare the link.
+Autogenerated categories can use the [`_category_.yml`](./autogenerated.mdx#category-item-metadata) file to declare the link.
 
 :::
 
@@ -287,7 +287,7 @@ module.exports = {
 };
 ```
 
-See it in action on the [i18n introduction page](../../../i18n/i18n-introduction.md).
+See it in action on the [i18n introduction page](../../../i18n/i18n-introduction.mdx).
 
 #### Embedding generated index in doc page {#embedding-generated-index-in-doc-page}
 
@@ -302,7 +302,7 @@ In this section, we will introduce the following concepts:
 <DocCardList items={useCurrentSidebarCategory().items}/>
 ```
 
-See this in action on the [sidebar guides page](index.md).
+See this in action on the [sidebar guides page](index.mdx).
 
 ### Collapsible categories {#collapsible-categories}
 
@@ -563,7 +563,7 @@ module.exports = {
 };
 ```
 
-Note how the two consecutive category shorthands are compressed into one object with two entries. This syntax generates a **sidebar slice**: you shouldn't see that object as one bulk item—this object is unwrapped, with each entry becoming a separate item, and they spliced together with the rest of the items (in this case, the "Learn more" link) to form the final sidebar level. Sidebar slices are also important when discussing [autogenerated sidebars](autogenerated.md).
+Note how the two consecutive category shorthands are compressed into one object with two entries. This syntax generates a **sidebar slice**: you shouldn't see that object as one bulk item—this object is unwrapped, with each entry becoming a separate item, and they spliced together with the rest of the items (in this case, the "Learn more" link) to form the final sidebar level. Sidebar slices are also important when discussing [autogenerated sidebars](autogenerated.mdx).
 
 Wherever you have an array of items that is reduced to one category shorthand, you can omit that enclosing array as well.
 

website/versioned_docs/version-2.0.1/guides/docs/sidebar/multiple-sidebars.mdx

@@ -10,8 +10,8 @@ You can create a sidebar for each **set of Markdown files** that you want to **g
 
 The Docusaurus site is a good example of using multiple sidebars:
 
-- [Docs](../../../introduction.md)
-- [API](../../../cli.md)
+- [Docs](../../../introduction.mdx)
+- [API](../../../cli.mdx)
 
 :::