Horizon users can now log in using domain-scoped tokens. Describe why/when this would be needed, the dependencies (keystone v3, etc), how to enable it, and how to test it.
SME has confirmed that the existing Keystone integration docs properly cover OPENSTACK_KEYSTONE_MULTIDOMAIN_SUPPORT. Closing bug. https://access.redhat.com/documentation/en/red-hat-openstack-platform/9/single/integrate-with-identity-service#configure_the_controller