Adding a note on how to create a geometry.xml file with only a DAGMC model.
Adding a note on how to create a geometry.xml file with only a DAGMC model.

walshjon/openmc,walshjon/openmc,walshjon/openmc,walshjon/openmc,amandalund/openmc,amandalund/openmc,amandalund/openmc,amandalund/openmc