Update notes for submitted changes

* PR: 1325095 Multi-backend support. Support for HDD/SSD Pools PR: 2913 Live migration script issue fixes    Volume needs to be detached only if its attached.    Change ownership permissions to nova:nova after mount PR: 1325095 - Support for NFS backend. PR: 2913 - Auto mount of NFS file system upon reboot added.    Used the 'bg' option to retry the mounts if the VM is not    reachable after boot. PR: 1336837 Added support for auto start of the nfs live vm.    The auto start will start all the VMs running in the node.