Pinafore is getting pretty mature as a project, so I decided to take some time to write about all the weird stuff to look out for in the codebase, for the benefit of a new contributor. I dunno if this kind of "here's all the weird stuff" overview belongs in CONTRIBUTING.md, but it seems to make sense to document it somewhere: https://github.com/nolanlawson/pinafore/blob/master/CONTRIBUTING.md#codebase-overview