Add api-ref for qos-rules-alias extension
Add api-ref for qos-rules-alias extension

Add api-ref for the qos-rules-alias extension.

Change-Id: I6d2d32f89e04a8ad83fae2a1183d572221881b90
Partial-Bug: #1777627

openstack/neutron-lib,openstack/neutron-lib,openstack/neutron-lib,openstack/neutron-lib