Fix typo in notes

doc/ci/pipelines.md

@@ -469,7 +469,7 @@ To illustrate its life cycle:
 1. GitLab Runner fetches the persistent pipeline ref and gets source code from the checkout-SHA.
 1. When the pipeline finished, its persistent ref is cleaned up in a background process.
 
-NOTE: **NOTE**: At this moment, this feature is on dy default and can be manually disabled
+NOTE: **NOTE**: At this moment, this feature is on by default and can be manually disabled
 by disabling `depend_on_persistent_pipeline_ref` feature flag. If you'd be interested in
 manually disabling this behavior, please ask the administrator
 to execute the following commands in rails console.