This builds git-bug, a distributed issue tracker that uses git as its
data store.
It also installs its man pages and shell completions. It is
recommended that users add git-bug to their system closure for these
extras to work, as they will not be picked up by the dispatch script.
Change-Id: I1595368e61b0bae8a9497abd023085cb90a521a6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/345
Reviewed-by: lukegb <lukegb@tvl.fyi>