Update draft index page
Update draft index page

Remove HA guide, RST conversion is finished.
Remove stray "conversion to RST" from one Install Guide.

Change-Id: Ic66cde98a5b61b36827de0fdbf041ebd96cd08dd

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