flextile: adding centeredmaster horiz example

config.def.h

@@ -523,7 +523,8 @@ static const Layout layouts[] = {
 	{ "[D]",      flextile,         { -1, -1, SPLIT_VERTICAL, TOP_TO_BOTTOM, MONOCLE, 0, NULL } }, // deck
 	{ "TTT",      flextile,         { -1, -1, SPLIT_HORIZONTAL, LEFT_TO_RIGHT, LEFT_TO_RIGHT, 0, NULL } }, // bstack
 	{ "===",      flextile,         { -1, -1, SPLIT_HORIZONTAL, LEFT_TO_RIGHT, TOP_TO_BOTTOM, 0, NULL } }, // bstackhoriz
-	{ "|M|",      flextile,         { -1, -1, SPLIT_CENTERED_VERTICAL, TOP_TO_BOTTOM, TOP_TO_BOTTOM, TOP_TO_BOTTOM, NULL } }, // centeredmaster
+	{ "|M|",      flextile,         { -1, -1, SPLIT_CENTERED_VERTICAL, LEFT_TO_RIGHT, TOP_TO_BOTTOM, TOP_TO_BOTTOM, NULL } }, // centeredmaster
+	{ "-M-",      flextile,         { -1, -1, SPLIT_CENTERED_HORIZONTAL, TOP_TO_BOTTOM, LEFT_TO_RIGHT, LEFT_TO_RIGHT, NULL } }, // centeredmaster horiz
 	{ ":::",      flextile,         { -1, -1, NO_SPLIT, GAPPLESSGRID, GAPPLESSGRID, 0, NULL } }, // gappless grid
 	{ "[\\]",     flextile,         { -1, -1, NO_SPLIT, DWINDLE, DWINDLE, 0, NULL } }, // fibonacci dwindle
 	{ "(@)",      flextile,         { -1, -1, NO_SPLIT, SPIRAL, SPIRAL, 0, NULL } }, // fibonacci spiral