Document Checkmate codebase

[parasj]

The current code base lacks any docs of any kind.

• Standardize on a single docstring format
• Finish documenting public interfaces
• Publish docs to a GH pages website using tool like https://github.com/facebook/docusaurus
• Autoreformat code on push to Github

Guides for good documentation best practices:

• https://docs.python-guide.org/writing/documentation/
• https://www.divio.com/blog/documentation/

[parasj]

A build process should autogenerate tutorials from ipython notebooks:

• https://github.com/pytorch/botorch/blob/master/scripts/parse_tutorials.py
• https://github.com/facebook/Ax/blob/master/scripts/make_tutorials.py

[parasj]

Docs should also autodeploy via a Github action: https://github.com/marketplace/actions/deploy-to-github-pages