Title: About Domain Controller Discovery and Failover

Describe the issue:
The following NOTE:

"NOTE
Starting a host controller with the --backup option will cause that controller to maintain a local copy of the domain configuration. This configuration will be used if the host controller is reconfigured to act as the domain controller."

Do not mention some important detail about the restore of the Original-DC. 

Suggestions for improvement:
According to KBASE:
"Note :
- Any changes made to the (master-backup) is not persisted once master-backup is unpromoted and it is an expected behaviour. Once we make the old DC the real master again, it only knows about its local config/deploys."

Additional information:
Please detail the procedure to restore the original DC and how to get the changes made to domain config during the downtime of Original Domain Controller