Add removed autogen note to README template

Author: aaron-lane

autogen/README.md

@@ -182,6 +182,11 @@ To more cleanly handle cases where desired functionality would require complex d
 
 The root module is generated by running `make generate`. Changes to this repository should be made in the [`autogen`](/autogen) directory where appropriate.
 
+Note: The correct sequence to update the repo using autogen
+functionality is the run `make generate && make generate_docs`.  This
+will create the various Terraform files, and then generate the
+Terraform documentation using `terraform-docs`.
+
 ## Testing
 
 ### Requirements