/draft-analysis and /filterset are fighting for space in docs sidebar

Whichever I include in API.md first shows in the sidebar of our mkdocs. It seems that whichever of the ### lines I do first will appear in the sidebar, but the :::api.server.foo bit seems to make the sidebar ignore later entries. I've filed issue #4 (closed) for it. I spent a looong time fighting with it and have decided to punt rather than delay the merge request any further.

I've assigned this to myself as penance, but if somebody knows the true way forward, please feel free to tackle it.