Document the public APIs (via jsdoc)

[Duckwhale]

Requires #2 to be completed.

Goals:

• [ ] All the functions implemented in the `C_`` namespaces should be properly documented (public API)
• [ ] The components (classes) used internally should be linked where relevant
• [ ] The global shorthands (debug/log output etc). should be documented too (https://jsdoc.app/tags-global.html)
• [ ] TBD: Library wrapper. e.g. NODE or BABYLON should be marked as external? (https://jsdoc.app/tags-external.html)
• [ ] The components should also be documented, as they actually implement much of the functionality (https://jsdoc.app/tags-classdesc.html)
• [ ] It should be noted when each API was first introduced (https://jsdoc.app/tags-since.html)
• [ ] All events that exist should be documented (the Events enum?) (https://jsdoc.app/tags-event.html)
• [ ] The global enumerations should be documented (https://jsdoc.app/tags-enum.html)
• [ ] Global shorthands, e.g. dump, should be marked as such (https://jsdoc.app/tags-borrows.html)
• [ ] Deprecated APIs should be marked as such (https://jsdoc.app/tags-deprecated.html)
• [ ] Complex default values (like Colors) should be documented (https://jsdoc.app/tags-default.html)
• [ ] All events triggered by an API should be documented (https://jsdoc.app/tags-fires.html)
• [ ] All events listened for by a component should be documented (https://jsdoc.app/tags-listens.html)
• [ ] All relevant documentation (tutorials, HOWTOs, and explanations) should also be linked
• [ ] The namespace itself should be described, by a summary line and a slightly longer description that introduces the reader to the concepts linked
• [ ] Documentation texts should ideally be written in markdown, which requires using the respective plugin (https://jsdoc.app/plugins-markdown.html)

[Duckwhale]

This should probably wait until the APIs are "final" (for the MVP), as well as properly tested.