1. Proposed title of this feature request
Add documentation for backing up external databases in ACS

2. What is the nature and description of the request?
Customer is looking for the steps you would have to preform to do a back up and restore for an external DB.

  I believe to back up the customer what follow whatever steps they normally would to back up a Postgres DB.
  Most likely they would run something like. 
  pg_dump -U <username> -d <database_name> -f <output_file_path>

  They would also want to make sure they have the ACS certificates backed up.
  `roxctl central backup --certs-only=true`

  They would then follow these instructions for a restore.

  a) Scale central to 0  (Please note this is only need for restores)

  b) Preform a Postgres restore
  pg_restore -U username -d new_database_name path/to/your/backup_file.tar_or_custom

  c) Restore your certificates
   https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_security_for_kubernetes/4.8/html/backup_and_restore/restore-acs#restore-cert-roxctl_restore-acs

3. Why does the customer need this? (List the business requirements here)
There currently is not documentation for this.

4. List any affected packages or components.
ACS