Write docs

[CaydenPierce]

There is a lot of docs here in the 4 READMEs. But, there's some problems.

Problems

• there are 4 READMEs
• the text wall makes it hard to find what you need when you need it
• the system has significantly evolved and thus some of the older README content isn't applicable, and some new information is missing

Solutions

• [ ] migrate docs to Read the docs - https://docs.readthedocs.io/en/stable/tutorial/
• [x] Write a "Before you start" guide
• [x] Write a "Setup" guide for those just setting up using APK download
• [x] Write a "Developer" setup guide for setting up ASP environment, ASG environment, and GLBOX

[CaydenPierce]

Did things differently (docs are in github wiki), but all done