Updated regex to cross reference nuclides with elements
Updated regex to cross reference nuclides with elements

amandalund/openmc,liangjg/openmc,walshjon/openmc,mit-crpg/openmc,walshjon/openmc,paulromano/openmc,johnnyliu27/openmc,bhermanmit/openmc,amandalund/openmc,paulromano/openmc,amandalund/openmc,mit-crpg/openmc,shikhar413/openmc,amandalund/openmc,walshjon/openmc,smharper/openmc,walshjon/openmc,bhermanmit/openmc,shikhar413/openmc,johnnyliu27/openmc,paulromano/openmc,wbinventor/openmc,liangjg/openmc,liangjg/openmc,paulromano/openmc,johnnyliu27/openmc,wbinventor/openmc,johnnyliu27/openmc,mit-crpg/openmc,wbinventor/openmc,shikhar413/openmc,smharper/openmc,liangjg/openmc,mit-crpg/openmc,smharper/openmc,shikhar413/openmc,smharper/openmc,wbinventor/openmc