Add section for checking production problems

.gitlab/issue_templates/Feature Flag Roll Out.md

@@ -37,6 +37,11 @@ Are there any other stages or teams involved that need to be kept in the loop?
 ### What can we monitor to detect problems with this?
 
 <!-- Which dashboards from https://dashboards.gitlab.net are most relevant? -->
+_Consider mentioning checks for 5xx errors or other anomalies like increase in 302 errors_
+
+### What can we check for monitoring production after rollouts?
+
+_Consider adding links to check for Sentry errors, Production logs for 5xx, 302s, etc._
 
 ## Rollout Steps