extended rule to apply monitors if set up accordingly

config.def.h

@@ -17,9 +17,9 @@ static const Bool topbar            = True;     /* False means bottom bar */
 static const char *tags[] = { "1", "2", "3", "4", "5", "6", "7", "8", "9" };
 
 static const Rule rules[] = {
-	/* class      instance    title       tags mask     isfloating */
-	{ "Gimp",     NULL,       NULL,       0,            True },
-	{ "Firefox",  NULL,       NULL,       1 << 8,       False },
+	/* class      instance    title       tags mask     isfloating   monitor */
+	{ "Gimp",     NULL,       NULL,       0,            True,        -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       False,       -1 },
 };
 
 /* layout(s) */