Merge pull request #22 from girder/readme

Author: brianhelba

README.md

@@ -3,6 +3,8 @@ A Terraform module to provision Girder infrastructure on AWS.
 
 This provides an EC2 machine, S3 assetstore, and outgoing SMTP credentials.
 
+See [full usage documentation at Terraform Registry](https://registry.terraform.io/modules/girder/girder/aws).
+
 ## Note on AWS Email Sending
 [Every AWS account must explicitly apply to send real emails](https://docs.aws.amazon.com/ses/latest/DeveloperGuide/request-production-access.html),
 once per Simple Email Service (SES) region.