Add empty SDG index

app/controllers/sdg/goals_controller.rb

@@ -0,0 +1,9 @@
+class SDG::GoalsController < ApplicationController
+  include FeatureFlags
+  feature_flag :sdg
+  load_and_authorize_resource
+
+  def index
+    @goals = @goals.order(:code)
+  end
+end