authz: Bitbucket Server ACLs documentation
Created by: tsenart
This PR adds documentation of, and a few code changes to, the Bitbucket Server ACLs feature, including the CHANGELOG.
Test plan:
I'd like to have reviewers follow the documentation that is added in this PR.
- Check-out this branch locally and run
./enterprise/dev/start.sh
. - Follow the docs to setup Bitbucket Server authorization.
- Validate that it works as expected (i.e. Sourcegraph enforces permissions defined in Bitbucket Server)