Team handbook
Fixes #268 (closed)
Brought team handbook (https://docs.google.com/a/gitlab.com/document/d/1YaRZGWCMuPYL3c8M1wknRxyS5352otj_xGc9ws8-nDs/edit#heading=h.7byzvdqkdjgx) into /team-handbook.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Fixes #268 (closed)
Brought team handbook (https://docs.google.com/a/gitlab.com/document/d/1YaRZGWCMuPYL3c8M1wknRxyS5352otj_xGc9ws8-nDs/edit#heading=h.7byzvdqkdjgx) into /team-handbook.