Add docs using Starlight

[BryceRussell]

The project needs better docs, we can use Starlight to create a documentation website

1. Create a Starlight project at the root of the repo inside /docs
2. Transfer markdown from the wiki into the src/content/docs folder
3. Configure Starlight (sidebar, title, description, home page, etc)
4. Move /images folder into docs at src/assets