Create docs for each package

[kayhhh]

Things aren't very documented right now, and the APIs for using lattice can be pretty ugly. I think there's a good opportunity to go through each package and add documentation (either in the readme, or create a proper docs site), and in the process think through the current APIs (components, systems, helper functions, etc) and clean things up.

[kayhhh]

github wiki seems like a good place going to finally do this soon 👍