Migrate docs to an easier to find place
Context
Currently our docs are... less than ideal. They are separated into three separate places, and they're long outdated. The more detailed parts on the wiki are almost invisible as nobody looks at the wiki, and I'm not sure many people even know it exists. We already have #746 (closed) to update the long-outdated parts, which I am currently actively working on, however this is also a good opportunity to rethink our documentation story in general.
Description
Personally, I think we need a dedicated docs page, perhaps on readthedocs. Here we can describe how to use the project, the nuances of various components and our "API". I think a centralised place is the best option for this.
Acceptance Criteria
People understand that we actually have documentation, where it is, and it is up to date.