Add comment to gen_resource_metadata.py

Author: deliahu

pkg/lib/aws/gen_resource_metadata.py

@@ -17,6 +17,7 @@
 from string import Template
 
 # https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/
+# China regions don't seem to support these endpoints (yet?)
 REGIONS = [
     "us-east-1",  # N. Virginia
     "us-east-2",  # Ohio