Doc update for cluster bind service

website/docs/r/container_bind_service.html.markdown

@@ -36,6 +36,8 @@ The following arguments are supported:
 * `namespace_id` - (Required, string) The Kubernetes namespace.
 * `service_instance_name` - (Optional, string) The name of the service that you want to bind to the cluster. Conflicts with `service_instance_id`.
 * `service_instance_id` - (Optional, string) The ID of the service that you want to bind to the cluster. Conflicts with `service_instance_name`.
+* `key` - (Optional, string) Specify an existing service key to use for the service binding.
+* `role` - (Optional, string) Specify the IAM role for the service key. This flag does not work if you specify an existing key to use or for services that are not IAM-enabled, such as Cloud Foundry services.
 * `org_guid` - (Optional, string) The GUID for the IBM Cloud organization associated with the cluster. You can retrieve the value from data source `ibm_org` or by running the `ibmcloud iam orgs --guid` command in the [IBM Cloud CLI](https://console.bluemix.net/docs/cli/reference/bluemix_cli/get_started.html#getting-started).
 * `space_guid` - (Optional, string) The GUID for the IBM Cloud space associated with the cluster. You can retrieve the value from data source `ibm_space` or by running the `ibmcloud iam space <space-name> --guid` command in the IBM Cloud CLI.
 * `account_guid` - (Optional, string) The GUID for the IBM Cloud account associated with the cluster. You can retrieve the value from data source `ibm_account` or by running the `ibmcloud iam accounts` command in the IBM Cloud CLI.