docs: blog + community + dogfood docs should use .mdx extension (#8507)

website/blog/2017-12-14-introducing-docusaurus.mdx

@@ -129,7 +129,7 @@ build
 
 ![](/img/docusaurus.svg)
 
-We welcome your [contributions](https://github.com/facebook/docusaurus/blob/master/CONTRIBUTING.md) to Docusaurus, whether you want to use it for your own site, you want to [contribute](https://github.com/facebook/docusaurus/blob/master/CONTRIBUTING.md) to the Docusaurus core or just have questions. Follow us on [GitHub](https://github.com/facebook/docusaurus) and [Twitter](https://twitter.com/docusaurus).
+We welcome your [contributions](https://github.com/facebook/docusaurus/blob/master/CONTRIBUTING.mdx) to Docusaurus, whether you want to use it for your own site, you want to [contribute](https://github.com/facebook/docusaurus/blob/master/CONTRIBUTING.mdx) to the Docusaurus core or just have questions. Follow us on [GitHub](https://github.com/facebook/docusaurus) and [Twitter](https://twitter.com/docusaurus).
 
 ## Acknowledgements
 

website/blog/2018-09-11-Towards-Docusaurus-2.mdx

@@ -18,7 +18,19 @@ There is a saying that the very best software is constantly evolving, and the ve
 
 It all started with this [RFC issue](https://github.com/facebook/docusaurus/issues/789) opened by [Yangshun](https://github.com/yangshun) towards the end of June 2018.
 
-<blockquote><h4><a href="https://github.com/facebook/docusaurus/issues/789">[RFC] Docusaurus v2 · Issue #789 · facebook/docusaurus</a></h4><p>These are some of the problems I'm seeing in Docusaurus now and also how we can address them in v2. A number of the ideas here were inspired by VuePress and other static site generators. In the current static site generators ecosystem, t...</p></blockquote>
+<blockquote>
+  <h4>
+    <a href="https://github.com/facebook/docusaurus/issues/789">
+      [RFC] Docusaurus v2 · Issue #789 · facebook/docusaurus
+    </a>
+  </h4>
+  <p>
+    These are some of the problems I'm seeing in Docusaurus now and also how we
+    can address them in v2. A number of the ideas here were inspired by VuePress
+    and other static site generators. In the current static site generators
+    ecosystem, t...
+  </p>
+</blockquote>
 
 Most of the suggested improvements are mentioned in the issue; I will provide details on some of issues in Docusaurus 1 and how we are going to address them in Docusaurus 2.
 

website/blog/2022-01-24-docusaurus-2021-recap/index.mdx

@@ -7,7 +7,7 @@ image: ./img/thumbnail.png
 
 Docusaurus has made great progress in 2021! We've seen a lot of traction and just crossed **30k stars on GitHub**!
 
-We've **reached full feature parity** with v1 after [the release of internationalization](../2021-03-09-releasing-docusaurus-i18n.md), [announced our **first beta**](../2021-05-12-announcing-docusaurus-two-beta/index.md), and welcomed **significantly more users** this year.
+We've **reached full feature parity** with v1 after [the release of internationalization](../2021-03-09-releasing-docusaurus-i18n.mdx), [announced our **first beta**](../2021-05-12-announcing-docusaurus-two-beta/index.mdx), and welcomed **significantly more users** this year.
 
 The **official v2 release** is just around the corner! Follow the [roadmap issue](https://github.com/facebook/docusaurus/issues/6113) for any latest news.
 
@@ -17,7 +17,7 @@ The **official v2 release** is just around the corner! Follow the [roadmap issue
 
 ## Highlights
 
-Let's begin by going over a few highlights this year. Remember the [todo-list](../2021-05-12-announcing-docusaurus-two-beta/index.md#whats-next) from half a year ago? Time to take it out again and see how far we've come!
+Let's begin by going over a few highlights this year. Remember the [todo-list](../2021-05-12-announcing-docusaurus-two-beta/index.mdx#whats-next) from half a year ago? Time to take it out again and see how far we've come!
 
 - **Internationalization**: officially released four months after its initial landing in late 2020. Seen great success in [many projects](/showcase?tags=i18n)
 - **Autogenerated sidebars**: no need to maintain a big `sidebars.js` anymore
@@ -118,7 +118,7 @@ We'd like to express our gratitude to [all the contributors in 2021](https://git
 
 - The core team: [Alexey Pyltsyn](https://github.com/lex111), [Sébastien Lorber](https://github.com/slorber), [Joshua Chen](https://github.com/Josh-Cena), and [Yangshun Tay](https://github.com/yangshun) for moderating the community, publicizing Docusaurus, triaging issues, and implementing new features
 - [Joel Marcey](https://github.com/JoelMarcey) for creating Docusaurus and supporting its development all along
-- The Algolia team for helping Docusaurus users [migrate to the new DocSearch](../2021-11-21-algolia-docsearch-migration/index.md) and answering search-related questions
+- The Algolia team for helping Docusaurus users [migrate to the new DocSearch](../2021-11-21-algolia-docsearch-migration/index.mdx) and answering search-related questions
 - All the active community members for making valuable code contributions, improving our documentation, and answering questions on Discord
 
 So long, 2021, and let's greet a great 2022!

website/blog/2022-08-01-announcing-docusaurus-2.0/index.mdx

@@ -95,7 +95,7 @@ Docusaurus was created at **Facebook Open Source** in **2017** (now [Meta Open S
 
 At that time, our solution was to **copy/paste a Jekyll template** over and over again. This naturally became **hard to maintain**, so we created a tool to **solve our own pain** once for all.
 
-**[Docusaurus v1 was born](../2017-12-14-introducing-docusaurus.md)!**
+**[Docusaurus v1 was born](../2017-12-14-introducing-docusaurus.mdx)!**
 
 ![Birth of Slash](/img/slash-birth.png)
 
@@ -129,7 +129,7 @@ Notice that the sample sites above use different colors, but still look quite th
 - We kept **everything good from v1**: docs, blog, pages, versioning, i18n...
 - We implemented **several new features**
 
-More details in the [Docusaurus 2 project announcement](../2018-09-11-Towards-Docusaurus-2.md) and [v1 to v2 migration guide](https://docusaurus.io/docs/migration)
+More details in the [Docusaurus 2 project announcement](../2018-09-11-Towards-Docusaurus-2.mdx) and [v1 to v2 migration guide](https://docusaurus.io/docs/migration)
 
 ## Who uses Docusaurus 2.0?
 
@@ -420,7 +420,7 @@ We'd like to express our gratitude to [all our contributors](https://github.com/
 - [Joel Marcey](https://github.com/JoelMarcey) for creating Docusaurus 1.0 and supporting the Docusaurus 2.0 project at Meta Open Source
 - [Paul O’Shannessy](https://github.com/zpao) for supporting the development of all the next versions of Docusaurus at Meta Open Source
 - [Eric Nakagawa](https://github.com/ericnakagawa) for creating our cutest mascot Slash
-- [Endilie Yacop Sucipto](https://github.com/endiliey) for his significant [initial work on Docusaurus v2](../2020-01-07-tribute-to-endi.md)
+- [Endilie Yacop Sucipto](https://github.com/endiliey) for his significant [initial work on Docusaurus v2](../2020-01-07-tribute-to-endi.mdx)
 - [Clément Vannicatte](https://github.com/shortcuts), [Kevin Granger](https://github.com/Shipow) and the whole Algolia team for their support
 - All the community members for making valuable code contributions, improving our documentation, and answering questions on [Discord](https://discordapp.com/invite/docusaurus)