LU-930 doc: fix lfs-project.1 quoting

LU-930 doc: fix lfs-project.1 quoting

Fix the quoting for the "-0" description, which otherwise is
formatted badly.  Improve the description to give more direction
as to the intended usage of this option.

Test-Parameters: trivial
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Id32c542a0697bc0c3c79775051d98d05be4ece5f
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55680
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>