This patch updates the Octavia documentation in support of the
OpenStack documentation migration[1].
[1] https://specs.openstack.org/openstack/docs-specs/specs \
/pike/os-manuals-migration.html
Change-Id: I97fd038b8050bfe776c3fca8336d9090f8236362
Depends-On: Ia750cb049c0f53a234ea70ce1f2bbbb7a2aa9454