Explore alternatives to mdbook for documentation

[joepio]

The current mdbook tool works decently, but has a couple of shortcomings:

• Basic, dated design
• No support for better codeblocks (e.g. for react / svelte), no support for filenames
• No support for component previews

We should consider some alternatives.

Astro Starlight

• Supports components and custom pages
• Looks good out of the box
• Uses Astro, which means we could use AtomicServer as data source (could be huge)

Challenges / questions

• Both Existing URLs and structure should be kept. mdbook uses a SUMMARY.md to set the structure. This may require some redirect strategy.
• Is the added benefit worth the effort?