adding tfdocs placement in README

Author: Peter Pouliot

README.md

@@ -47,6 +47,8 @@ This can also be used as a terraform module.   The [examples](examples) director
 ```
 terraform init && terraform plan && terraform apply -auto-approve
 ```
+<!-- BEGIN_TF_DOCS -->
+<!-- END_TF_DOCS -->
 
 ## References