Document On-Prem MMS Admin Options

Admin settings page for on-prem MMS has some options to enable/disable under various headers. Would be useful to document what they do.

As I loosely understand it:

• Assignment
  Whether you want the daemon to take any more jobs or not. As disks fill up on daemon machines, you may want to disable this so no box gets overloaded.

• Backup jobs
  Normal lifecycle of doing backups. Daemons wont take on any more work if disabled (i.e. you are doing maintenance on a daemon box)

• Restore jobs
  Whether this daemon can do restore jobs or not. You may wish to have a dedicated restore daemon in the cluster. PITs are build on the daemon.

• Resource usage
  Metrics on how much of your blockstore is dead/alive (dead blockstore requires garbage collection).

• Garbage collection
  Is apparently network intensive and you want to control who does that

Would be nice to flesh these out a little and add?