docs: Small Open vSwitch devref tweaks
docs: Small Open vSwitch devref tweaks

 - renames OpenVSwitch to Open vSwitch
 - fixes formating of ovs-vsctl commands
 - adds vlan tags to vlan aware vms plugging schemas

TrivialFix

Change-Id: I04b5ea13c708705a96e8ea7665b493ee152c7bbb

huntxu/neutron,mahak/neutron,sebrandon1/neutron,openstack/neutron,noironetworks/neutron,eayunstack/neutron,openstack/neutron,openstack/neutron,igor-toga/local-snat,cloudbase/neutron,igor-toga/local-snat,eayunstack/neutron,sebrandon1/neutron,mahak/neutron,mahak/neutron,huntxu/neutron,cloudbase/neutron,noironetworks/neutron