fix one typo in update-children example
diff --git a/guide/blueprints/workflow/examples/aws-cfn-stacks/aws-discoverer.yaml b/guide/blueprints/workflow/examples/aws-cfn-stacks/aws-discoverer.yaml
index b82f6e2..a04c0fb 100644
--- a/guide/blueprints/workflow/examples/aws-cfn-stacks/aws-discoverer.yaml
+++ b/guide/blueprints/workflow/examples/aws-cfn-stacks/aws-discoverer.yaml
@@ -12,5 +12,5 @@
           period: 1m
           steps:
             - ssh aws cloudformation describe-stacks
-            - transform output | json | set describe_stacks_output_json
+            - transform stdout | json | set describe_stacks_output_json
             - update-children type aws-cfn-discovered-stack-sample id ${item.StackId} from ${describe_stacks_output_json.Stacks}