Stating that certificate it is required when doing SSL on ELB.

playbooks/aws/README.md

@@ -65,6 +65,7 @@ openshift_release: # example: v3.7
 openshift_pkg_version: # example: -3.7.0
 openshift_aws_ssh_key_name: # example: myuser_key
 openshift_aws_base_ami: # example: ami-12345678
+# These are required when doing SSL on the ELBs
 openshift_aws_iam_cert_path: # example: '/path/to/wildcard.<clusterid>.example.com.crt'
 openshift_aws_iam_cert_key_path: # example: '/path/to/wildcard.<clusterid>.example.com.key'
 ```