Big Boi Refactor

[Sammy99jsp]

This is like a duplicate of #135, but its for my own sanity (I want to delete a bunch of branches on my fork).

This aims to:

• [x] Improve CI by adding auto documentation building.
• [ ] Focus heavily on documentation, and code organisation.
• [ ] Get feature-parity with the existing codebase.
• [ ] Update codebase to use newer Smithay rev.

Newer features will come later on a different PR.

[Sammy99jsp]

You'll be able to see the documentation for dev here: https://sammy99jsp.github.io/Compositor/av_compositor/index.html.