feat: React.dev docs

[gombosg]

Fixes #1997.
Test with: bundle exec thor docs:generate react
TODOs:

• Basic scraper
• Sanitize titles
• Add categories
• Fix code examples
• Remove some more extra styling divs
• Syntax highlighting
• Update icon
• Add "Learn" section
• Strip styling classes
• Address category main pages (1 level breadcrumb)
• Fix loading <figure> images (base64 is wrong)
• Prefix with category group (e.g. RSC, react-dom etc.)
• Fix callouts (canary, you will learn, pitfalls)
• Fix "show more" expansions
• Transform recipe links to outgoing links (those example tabs can't be rendered properly, they need JS) - we can live with it in the first release
• Add more search entries - we won't need them IMO

---

If you’re adding a new scraper, please ensure that you have:

• Tested the scraper on a local copy of DevDocs
• Ensured that the docs are styled similarly to other docs on DevDocs

• Added these files to the public/icons/your_scraper_name/ directory:
  • 16.png: a 16×16 pixel icon for the doc
  • 16@2x.png: a 32×32 pixel icon for the doc
  • SOURCE: A text file containing the URL to the page the image can be found on or the URL of the original image itself

If you're updating existing documentation to its latest version, please ensure that you have:

• Updated the versions and releases in the scraper file
• Ensured the license is up-to-date
• Ensured the icons and the SOURCE file in public/icons/your_scraper_name/ are up-to-date if the documentation has a custom icon
• Ensured self.links contains up-to-date urls if self.links is defined
• Tested the changes locally to ensure:
  • The scraper still works without errors
  • The scraped documentation still looks consistent with the rest of DevDocs
  • The categorization of entries is still good

[gombosg]

Some fixes are still pending but it's looking good already!
Draft comments are welcome in the meantime, @simon04! 🥰

The only real problem I'm facing is that some figures are not displaying well in the Learn pages. The PNG seems to be transformed to Base64 with a wrong value.

[gombosg]

@simon04 WDYT about the PR's direction? I'm happy to finish it in the coming days.

[simon04]

Hi @gombosg, thank you for this great work – I love it! Please go ahead and let me know when/where I should help out.

Regarding the broken images, simply remove the srcset attribute – css('img').remove_attr('srcset')

[gombosg]

It's ready for review @simon04! It looks good, as per my quality standards. 🤓

• In the end I left the recipe/challenges etc. blocks as is. They either don't appear or appear okay. The user can always alt-o to the original docs. We can improve this in further PRs.
• I left out additional search entries, they seemed to be too distracting, so we only have pages which correspond to items in the left sidebar.
• $qq do we support hidden search entries that are searchable but don't appear in the left sidebar?
• The page ships both light and dark images. I stripped dark ones but with some CSS media queries we could actually use both in DevDocs as well. This is another future improvement.

Note: React 19 has just been released. We could add it before merging, or we can merge that in a subsequent PR. I'd opt for the latter if possible, as it's more incremental that way.

[simon04]

Awesome, thank you!