RHDEVDOCS-6460: Content creation for handling YAML parsing errors in PAC

Incorporated SME review comment

Author: Dhruv-Soni11

modules/op-monitoring-pipeline-run-status-using-pipelines-as-code.adoc

@@ -50,6 +50,16 @@ For webhook, when the event is a pull request, the status is added as a comment
 .Failures
 If a namespace is matched to a `Repository` custom resource definition (CRD), {pac} emits its failure log messages in the Kubernetes events inside the namespace.
 
+[discrete]
+.YAML parting error messages in pull request comments
+{pac} detects and reports YAML errors in `PipelineRun` definitions within the `.tekton` directory. When an invalid `PipelineRun` YAML is found in a pull request (PR) event, {pac} creates a comment on the pull request (PR) describing the error and halts the execution of other correctly formatted pipeline runs. Consider the following scenarios:
+
+* If the PR is updated and new YAML errors are detected, the comment is updated with the latest information.
+* If no new errors are found, the existing comment remains unchanged and is not deleted.
+* If a validation issue is found, {pac} logs the error in the user namespace events log and the {pac} controller log.
+
+These error scenarios do not halt the execution of valid pipeline runs because the system continues to process validated and matched pipeline runs, preventing a single validation problem from disrupting the entire automation workflow.
+
 [discrete]
 .Status associated with Repository CRD
 The last 5 status messages for a pipeline run is stored inside the `Repository` custom resource.