NOISSUE add flat icon theme by Michael

It's the google icon font, all scalable and grey.

application/main.cpp

@@ -49,6 +49,7 @@ int main(int argc, char *argv[])
 		Q_INIT_RESOURCE(pe_colored);
 		Q_INIT_RESOURCE(OSX);
 		Q_INIT_RESOURCE(iOS);
+		Q_INIT_RESOURCE(flat);
 		return app.exec();
 	}
 	case MultiMC::Failed: