LU-16386 utils: Improve mkfs.lustre.8 man page

LU-16386 utils: Improve mkfs.lustre.8 man page

This patch imporves the
- Options section of "--version" argument
- Adds "--version" option to examples section

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I7fd3e7f1ea9a313a33db5620a92a595f2c4bd36f
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49384
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>