fixed description of CMFD mesh
fixed description of CMFD mesh

paulromano/openmc,smharper/openmc,liangjg/openmc,bhermanmit/openmc,mit-crpg/openmc,smharper/openmc,shenqicang/openmc,walshjon/openmc,liangjg/openmc,paulromano/openmc,shikhar413/openmc,walshjon/openmc,mjlong/openmc,mjlong/openmc,amandalund/openmc,samuelshaner/openmc,amandalund/openmc,lilulu/openmc,sxds/opemmc,samuelshaner/openmc,bhermanmit/openmc,samuelshaner/openmc,paulromano/openmc,smharper/openmc,amandalund/openmc,amandalund/openmc,johnnyliu27/openmc,nhorelik/openmc,shikhar413/openmc,smharper/openmc,wbinventor/openmc,walshjon/openmc,mit-crpg/openmc,johnnyliu27/openmc,kellyrowland/openmc,samuelshaner/openmc,nhorelik/openmc,shenqicang/openmc,liangjg/openmc,wbinventor/openmc,shikhar413/openmc,sxds/opemmc,lilulu/openmc,mit-crpg/openmc,bhermanmit/cdash,paulromano/openmc,mit-crpg/openmc,lilulu/openmc,walshjon/openmc,johnnyliu27/openmc,kellyrowland/openmc,johnnyliu27/openmc,shikhar413/openmc,wbinventor/openmc,liangjg/openmc,wbinventor/openmc