Add link to the v3 client api doc

There was no link from the main page to the v3 client API doc so
there's no easy way to get to it or to know that it's there. This
adds the link.

Change-Id: I3fd49eedcf7b79f6d810ed22cfcffba4ce47dece
Fix keystone command man page

The overline/underline for the title was too short which generated
an error.

Change-Id: I2ba30ff9c819c425d5973c8cf5fd92d5642b5885
Merge "Add link to the v3 client api doc"
Merge "Fix keystone command man page"
Test commit