Description of problem:

We need to document all of the following pools.

      pool_names.insert(zone.domain_root);
      pool_names.insert(zone.metadata_heap);
      pool_names.insert(zone.control_pool);
      pool_names.insert(zone.gc_pool);
      pool_names.insert(zone.log_pool);
      pool_names.insert(zone.intent_log_pool);
      pool_names.insert(zone.usage_log_pool);
      pool_names.insert(zone.user_keys_pool);
      pool_names.insert(zone.user_email_pool);
      pool_names.insert(zone.user_swift_pool);
      pool_names.insert(zone.user_uid_pool);
      pool_names.insert(zone.otp_pool);
      pool_names.insert(zone.roles_pool);
      pool_names.insert(zone.reshard_pool);

We do not have documentation for: 

zone.metadata_heap
zone.opt_pool
zone.roles_pool
zone.reshard_pool