Document the following:
* -R can take a group
* -S can take a group and provision
I also split up the -S description into multiple paragraphs because it
was getting too large.
Signed-off-by: Nathan Jones <nathanj@insightbb.com>
[Dan: added some feedback from the ML, rewrapped lines]
Signed-off-by: Dan McGee <dan@archlinux.org>