add menu api

app/controllers/api/restaurant/item_sets_controller.rb

@@ -0,0 +1,9 @@
+class Api::Restaurant::ItemSetsController < Api::ApiController
+
+  #Description
+  # Pull the default menu details and also other available (active) menus
+  # Input Params - order_id
+  def index
+    @item_sets = ItemSet.all
+  end
+end