Clarify git_data_dir docs
There is a note regarding configuration for 8.10, but it is using the 9.x configuration settings. We should remove the reference to 8.10.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
There is a note regarding configuration for 8.10, but it is using the 9.x configuration settings. We should remove the reference to 8.10.