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

I want to use a docwidget in the docs to display the portion of app.yaml that needs to be configured.
GoogleCloudPlatform/php-docs-samples,GoogleCloudPlatform/php-docs-samples,GoogleCloudPlatform/php-docs-samples,GoogleCloudPlatform/php-docs-samples,GoogleCloudPlatform/php-docs-samples