Add documentation for building and usage

[rk1a]

[rk1a]

related: #19

[rk1a]

Should add a getting started notebook for how to build to README: https://colab.research.google.com/drive/148B6CCzzeWWai8-t7G-4yL3k87p1Ac05?usp=sharing

[AI-WAIFU]

Building documentation now present in #70

[rk1a]

New build process with makefile should be added to #73