PEP and properly document everything

[Godley]

• Every method should have a docstring within reason
• I did run autopep8 about a week back so it should all be compliant but should avoid doing that and actually stick with pep8
• previously I used pdoc to generate docs.charlottegodley.co.uk/MuseParse so should try to use that again but need to figure out how to generate that again because I can't remember
• Add a build step on CI to build the docs and chuck them on that website if poss