GitLab

Even though we have the readme people keep on wondering why git-backup
was created at all. Rafael suggested to share the original announcement
email "so we dont forget later on why we have this."

-> Do that.

/suggested-and-reviewed-by @rafael
/reviewed-on kirr/git-backup!10
/reviewed-on https://www.erp5.com/group_section/forum/Gitlab-backup-zDVMZqaMAK/view?list_start=8&reset=1#2074720302