LUDOC-300 intro: update Lustre production usage numbers

LUDOC-300 intro: update Lustre production usage numbers

Update the Lustre production usage numbers based on more recent
system configurations.

Link to the file and filesystem size limits from the introduction.
Fix table reference links to reference the table and not the title.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: Ie1be90b021a335d43160b05870ae37c631e157cb
Reviewed-on: http://review.whamcloud.com/22759
Tested-by: Jenkins
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Joseph Gmitter <joseph.gmitter@intel.com>