Document QoS bandwidth limit direction extension
Document QoS bandwidth limit direction extension

Closes-Bug: #1733383

Change-Id: I235abd3c44455c5c19ea29404ff1b9c3a8b050aa
Signed-off-by: Michal Kelner Mishali <5c58114e82cdbe8f8b208a55e01273a9a20ee696@vmware.com>

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