Add doc changes for upgrade with incomplete PVCs
Add doc changes for upgrade with incomplete PVCs

Signed-off-by: Ganesh Maharaj Mahalingam <e84b6eb1374b2034268ad16b797fbec9318eafab@intel.com>

rook/rook,rook/rook,rook/rook,rook/rook,rook/nfs,rook/nfs,rook/nfs,rook/rook