clarify DB/Redis HA docs
This is a first pass at making the HA docs a little bit clearer. Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/31829
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
This is a first pass at making the HA docs a little bit clearer. Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/31829
approved this merge request
merged
mentioned in commit 62b0eb2c