Replace
Ceph distributed file system
with
Ceph distributed storage system
to help reduce the idea that Ceph is just a file system.
Signed-off-by: Loic Dachary <loic@dachary.org>
Includes various content cleanups: layout of synopsis, layout
of comments in examples, typos.
Signed-off-by: Tommi Virtanen <tommi.virtanen@dreamhost.com>
