Added links to Shared File Systems API books
Added links to Shared File Systems API books

On index page added 2 links to the documentation of
Shared File Systems API, that is already published:
http://developer.openstack.org/api-ref-share-v2.html
http://developer.openstack.org/api-ref-share-v1.html

Change-Id: Ia0ced14ca0baf4a090d4b816652c6be702e19245
Closes-Bug: #1502163

openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals