Applied naming conventions to Keystone service descriptions

After noticing some inconsistency among Keystone service
descriptions, I applied the naming conventions defined here:

https://wiki.openstack.org/wiki/Documentation/Conventions

Change-Id: Iace29f5fa4d29f93104f34da780d42f6d2f62d8f
Closes-Bug: #1287958
Fix link for training-cluster-scripts

Currently we link to a copy of the scripts on docs.openstack.org - and
that location does not exist.

Instead of putting this data on docs.openstack.org, let's give a
reference to github and distribute it from there.

Change-Id: I4dc7f31a3a50520ccef16db7e4ff0b54d02d89ff
Closes-Bug: #1282874
Merge "Applied naming conventions to Keystone service descriptions"
Merge "Fix link for training-cluster-scripts"