Prepare Docs for upcoming Docusaurus v4.0's breaking changes.

[BluWizard10]

Docusaurus v4.0 is going to be releasing sometime in the near future, which will introduce a lot of breaking changes that must be resolved as soon as possible for the Creators Docs to be future-proofed.

Here's what's going on:

• Docusaurus Faster is now recommended. Docusaurus Faster facebook/docusaurus#10556
• Admonition Titles must be migrated from :::note Title to the directive form :::note[Title] since mdx1CompatDisabledByDefault disables the legacy parser.
• Rename all .md files to .mdx to align with v4 conventions, as v4 will fully enforce MDX v3.
• Any HTML comments must be converted to use JSX comment syntax.
• Link references to .md files must be updated to renamed .mdx files.

Full details from Docusaurus v3.10 release for further reading: https://docusaurus.io/blog/releases/3.10

[slorber]

Note:

• Docusaurus Faster is recommended but we'll keep support for Webpack/Babel in v4
• Admonitions title with the old syntax will remain supported in v4, but you'll have to enable it manually with markdown.mdx1Compat.admonitions: true
• You don't need to rename to .mdx, however we encourage you to do so
• HTML comments can be supported in v4 with markdown.mdx1Compat.comments: true

In v4 we are only changing defaults to encourage you to use our new build infra, and MDX as it is natively designed to work. However, you can revert the behavior changes we apply and migrate incrementally when ready.