docs: tuning docs for nfs setup
docs: tuning docs for nfs setup

1. remove missing provisioner.yaml
2. modified statement description

Signed-off-by: Deshi Xiao <ce6baa22c65be7d48949d3dd3d85a2e1d4063969@gmail.com>

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