Title: About Domain Controller Discovery and Failover

Describe the issue: There is no information about the "unpromoting" procedure.


Suggestions for improvement:
A new procedure with the information to "unpromote" the backup DC could be added.
As https://access.redhat.com/support/cases/#/case/01279577?commentId=a0aA000000Cy5dDIAR, write-remote-domain-controller pointing it back to the original DC is needed. For example:

/host=HOST_NAME:write-remote-domain-controller(host="${jboss.domain.master.address}",port="${jboss.domain.master.port:9999}",security-realm="ManagementRealm",username="${username}")


Additional information:
As this comment: https://access.redhat.com/support/cases/#/case/01279577?commentId=a0aA000000CxTPQIA3 several backup host can be configured, but this information is also missing in the documentation.

<domain-controller>
    ...
    <static-discovery name="primary" host="<DC-IPAddress>" port="9999"/>
    <static-discovery name="backup1" host="<Host1-Address>" port="9999"/>
    <static-discovery name="backup2" host="<Host2-Address>" port="9999"/>
    <static-discovery name="backup3" host="<Host3-Address>" port="9999"/>
    ...
</domain-controller>