Consider adding JSDoc or Leafdoc comments

[prushforth]

While this probably isn't necessary or possible to generate MDN-style element and DOM api documentation, it might help in the case of external JavaScript APIs, such as we have with the Custom Projections API and the GeoJSON API, where the target user is a JavaScript Web developer. It would remain to be determined how to generate the appropriate md files that can be incorporated into Docusaurus. Considerations, comments, ideas etc. appreciated below.

[ahmadayubi]

This would be really nice to have not just for users of MapML APIs but also potential contributors.

Without types/JSDoc, you need to have a lot of context to make changes. Standalone JavaScript in a large code base can lead to unexpected issues and make debugging harder for new comers (like myself  😅).