endpoints: update comment and add region tags (GoogleCloudPlatform#519)

I want to use a docwidget in the docs to display the portion of app.yaml that needs to be configured.

Author: navinger

endpoints/getting-started/app.yaml

@@ -4,13 +4,15 @@ env: flex
 runtime_config:
   document_root: .
 
+# [START configuration]
 endpoints_api_service:
   # The following values are to be replaced by information from the output of
-  # 'gcloud service-management deploy openapi.yaml' command. If you have
+  # 'gcloud endpoints services deploy openapi-appengine.yaml' command. If you have
   # previously run the deploy command, you can list your existing configuration
   # ids using the 'configs list' command as follows:
   #
   #     gcloud endpoints configs list --service=YOUR-PROJECT-ID.appspot.com
   #
-  name: ENDPOINTS SERVICE NAME
-  config_id: ENDPOINTS CONFIG ID
+  name: ENDPOINTS-SERVICE-NAME
+  config_id: ENDPOINTS-CONFIG-ID
+# [END configuration]