Add Otavia docs for xena release
Add Otavia docs for xena release

Octavia projects were not initially included in the Xena project index.

Change-Id: Ib4b8ec00e19d00973d2e69cf3686abdd3fd55d22

openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals