update example comments

Author: magreenbaum

examples/complete/main.tf

@@ -377,7 +377,10 @@ module "s3_bucket" {
   ]
 
   # metadata configuration example
+  # https://docs.aws.amazon.com/AmazonS3/latest/userguide/metadata-tables-overview.html
   # https://docs.aws.amazon.com/AmazonS3/latest/userguide/metadata-tables-configuring.html
+  # only available in supported regions: https://docs.aws.amazon.com/AmazonS3/latest/userguide/metadata-tables-restrictions.html
+
   # create_metadata_configuration                 = true
   # metadata_inventory_table_configuration_state  = "ENABLED"
   # metadata_journal_table_record_expiration      = "ENABLED"