turn on Keyhive in patchwork.inkandswitch.com

[chee]

this will need some other changes too

• do not create keyhive docs by default in sideboard
• move sharing config to a doc titlebar tool?

can't remember if there are others, please edit this if you can think of some

will need some coördination with Keyhive team.

note: i'm unsure if we should do this while we believe a new Keyhive is going to make docs made now unreadable. if there's a ticket for that work* i'd like to mark it as a blocker for this ticket

*migrating a dependency beginning with b that i find it impossible to remember the name of