Add syntax highlighting to WIT documentation

[mkatychev]

WIT code is currently unhighlighted as highlight.js does not support WIT currently. Using the mdbook-treesitter preprocessor is a good avenue to add syntax highlighting for all WIT codeblocks in the documentation, working example of it in action:
https://mkatychev.github.io/component-docs/design/wit.html#worlds

Caveat:
Current mdbook-treesitter outputs grammar logic used for highlighting as dylib file (wit.so) and work is needed adding emscripten support to output a wit.wasm grammar file.

[kate-goldenring]

Having WIT syntax highlighting would be great. @mkatychev have you explored updating a highlight.js file? Seems like that is MDbooks default path for adding new syntax highlighting. Here is an example PR where someone adds one.

[mkatychev]

@kate-goldenring I think the advantages of using tree-sitter over base highlight.js are pretty significant overy hand implementing highlight.js:

• the work has already been done for specyifying the grammar including support for new features such as gates
• there is already extensive testing of the grammar for old and new features alike
• Any changes we make to tree-sitter-wit also benefit the WIT formatter I've implemented in topiary
• tree-sitter grammar can target a WIT output meaning that the highlighting and formatting additions/fixes exten far beyond just highlight.js

[kate-goldenring]

Taking a look at the mdbook-treesitter project, it looks like it "simply translates the tree-sitter highlighting into highlightjs one." So, in the end it sounds like we get the best of both worlds. Does that mean mdbook-treesitter outputs a highlight.js file that we could just regenerate in CI?

[mkatychev]

Yep, that's what it does without the duplicitous maintenance oh having a separate highlight.js grammar to maintain!