move menu and playground to konstructor

konstructor/menu.go

@@ -0,0 +1,18 @@
+package konstructor
+
+type MenuMap map[string]Menu
+
+type MenuLayout struct {
+	Background string
+}
+
+type MenuItem struct {
+	ID      string
+	Label   string
+	Handler func()
+}
+
+type Menu struct {
+	MenuLayout MenuLayout
+	MenuItems  []MenuItem
+}