Update iam.tf

modules/gcs/iam.tf

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+# tfdoc:file:description IAM bindings
+
 resource "google_storage_bucket_iam_binding" "authoritative" {
   for_each = var.iam
   bucket   = google_storage_bucket.bucket.name
@@ -49,4 +51,4 @@ resource "google_storage_bucket_iam_member" "bindings" {
       description = each.value.condition.description
     }
   }
-}
+}