opt: add back vertical grid layout

src/layout/layout.h

@@ -23,6 +23,7 @@ enum {
 	CENTER_TILE,
 	VERTICAL_SCROLLER,
 	VERTICAL_TILE,
+	VERTICAL_GRID,
 };
 
 Layout layouts[] = {
@@ -37,4 +38,5 @@ Layout layouts[] = {
 	{"VS", vertical_scroller, "vertical_scroller",
 	 VERTICAL_SCROLLER},								   // 垂直滚动布局
 	{"VT", vertical_tile, "vertical_tile", VERTICAL_TILE}, // 垂直平铺布局
+	{"VG", vertical_grid, "vertical_grid", VERTICAL_GRID}, // 垂直格子布局
 };