Update README
Update README

0.14 is not released, merge changes back to 0.13 and cleanup a bit.

Change-Id: I619f975321d88011cd6af4e12ecf19bbe9ba0b8a

savinash47/openstack-doc-tools,openstack/openstack-doc-tools,openstack/openstack-doc-tools,savinash47/openstack-doc-tools,savinash47/openstack-doc-tools