Create some sort of API reference docs

[Akuli]

rdbende wants these. Taken from #1308:

I rarely look at the docstrings, but rather use the web docs. It's easier for me to find what I'm looking for, but then go usually back to the source code, to read, what it actually does :D

I ~~originally wanted to delete~~ have deleted akuli.github.io/porcupine because it wasn't very well mainted. Maybe we could replace it with something like pydoc-markdown.