[meta] docs overhaul

[charles-cooper]

boa docs need an overhaul. they also need to document all of titanoboa.

cf. https://docs.divio.com/documentation-system/

[rafael-abuawad]

How can we get this started? @charles-cooper?

[charles-cooper]

Hmm it's a good question. There are a lot of undocumented features currently, so one could either
a) start with documenting them or
b) start reorganizing the docs per the divio link above