add quota ID for static provisioning (#319)

content/docs/csidriver/features/powerscale.md

@@ -22,6 +22,9 @@ You can use existent volumes from the PowerScale array as Persistent Volumes in
 1. Open your volume in One FS, and take a note of volume-id.
 2. Create PersistentVolume and use this volume-id as a volumeHandle in the manifest. Modify other parameters according to your needs.
 3. In the following example, the PowerScale cluster accessZone is assumed as 'System', storage class as 'isilon', cluster name as 'pscale-cluster' and volume's internal name as 'isilonvol'. The volume-handle should be in the format of <volume_name>=_=_=<export_id>=_=_=<zone>=_=_=<cluster_name>
+4. If Quotas are enabled in the driver, it is recommended to add the Quota ID to the description of the NFS export in the following format: 
+`CSI_QUOTA_ID:sC-kAAEAAAAAAAAAAAAAQEpVAAAAAAAA`
+5. Quota ID can be identified by quering the PowerScale system.
 
 ```yaml
 apiVersion: v1