Document Port properties
Document Port properties

Add description to the various properties of the OS::Neutron::Port
resource.

Closes-Bug: #1224176
Change-Id: I910730996409073a1ceaa483d3ef2ce25aac3dc6

NeCTAR-RC/heat,srznew/heat,redhat-openstack/heat,openstack/heat,takeshineshiro/heat,cwolferh/heat-scratch,rh-s/heat,steveb/heat,dragorosson/heat,ntt-sic/heat,ntt-sic/heat,pratikmallya/heat,gonzolino/heat,jasondunsmore/heat,takeshineshiro/heat,pratikmallya/heat,noironetworks/heat,dims/heat,noironetworks/heat,rdo-management/heat,miguelgrinberg/heat,openstack/heat,maestro-hybrid-cloud/heat,pshchelo/heat,dims/heat,steveb/heat,cwolferh/heat-scratch,rh-s/heat,maestro-hybrid-cloud/heat,cryptickp/heat,srznew/heat,dragorosson/heat,miguelgrinberg/heat,NeCTAR-RC/heat,redhat-openstack/heat,gonzolino/heat,pshchelo/heat,rdo-management/heat,jasondunsmore/heat,cryptickp/heat