Adding comment about available regions
@@ -5,6 +5,8 @@ instances:
## @param region_name - string - optional
## AWS region to run PricingService requests in.
+ ## As of writing, only us-east-1 and ap-south-1 are supported.
+ ## See https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/using-pelong.html
#
# - region_name: <REGION>
