Add automigration MDX1 HTML comments to MDX2 JSX comments

[shilman]

See #18554

[ndelangen]

@shilman replacing HTML-comment with JS comments in all MDX files, should do the trick right?

We likely will have to do this with a RegExp, considering the MDX compiler actually is not able to parse the file..

1. find all MDX files
2. search for HTML comments globally over each file: /\<\!\-\-(.+)\-\-\>/
3. replace each occurrence with {/* $1 */}

This seems like the best place for it:

storybook/code/lib/cli/src/automigrate/fixes/mdx-1-to-2.ts

Line 12 in 99cf92f

return mdx.replace(MDX1_SCRIPT_START, '<style>\n {`').replace(MDX1_SCRIPT_END, ' `}\n</style>');

[shilman]

Yup!!

[slorber]

Docusaurus maintainer 👋 also trying to upgrade to MDX 2 facebook/docusaurus#8288

Worth taking into consideration that comments might be nested inside HTML code blocks 🤪

<!-- md comment -->

```html
<div>
  <!-- HTML comment (do not transform) -->
</div>
```

[ndelangen]

[shilman]

Crikey!! I just released https://github.com/storybookjs/storybook/releases/tag/v7.0.0-beta.26 containing PR #20349 that references this issue. Upgrade today to the @next NPM tag to try it out!

npx sb@next upgrade --prerelease

Closing this issue. Please re-open if you think there's still more to do.