add template submitters

app/controllers/api/templates_controller.rb

@@ -15,7 +15,8 @@ module Api
     def template_params
       params.require(:template).permit(:name,
                                        schema: [%i[attachment_uuid name]],
-                                       fields: [[:uuid, :name, :type, :required,
+                                       submitters: [%i[name uuid]],
+                                       fields: [[:uuid, :submitter_uuid, :name, :type, :required,
                                                  { options: [], areas: [%i[x y w h attachment_uuid page]] }]])
     end
   end