docs/wiki/guidelines

[andrewj-brown]

Need to write this one down somewhere so I (hopefully) stop forgetting.

The documentation is in dire need of an overhaul. The wiki has only a brief explanation of environment variables!

The README needs an overhaul; it should be significantly more minimal and link heavily to a fleshed-out wiki describing setup and documenting the main points of every individual cog. Workflow runs also need documentation, keeping in mind our "target audience" is a 1001 student who hasn't touched static typesystems yet.

It'd also be good to get contribution/security/whatever guidelines and PR/issue templates setup, per github's recommendations for community repos.

[andrewj-brown]

commenting to note that we're hashing out error-handling strategies, which is a topic that'll need a wiki page eventually.