Adapted the DustGridPlotFile documentation to its new inheritance
Adapted the DustGridPlotFile documentation to its new inheritance

SKIRT/SKIRT,raesjo/SKIRTcorona,raesjo/SKIRT,raesjo/SKIRTcorona,raesjo/SKIRTcorona,raesjo/SKIRT,SKIRT/SKIRT,SKIRT/SKIRT,raesjo/SKIRT