https://docs.openshift.com/container-platform/4.16/observability/monitoring/troubleshooting-monitoring-issues.html 

Add new section to this page "troubleshooting alertmanager configurations" 

From the support team: "every cluster that is deployed has the `AlertmanagerReceiversNotConfigured`  alert firing by default. We still get cases for this, I think we do have a section in reference to this but it takes you through adding a receiver in the GUI."

To enhance our documentation, a new section called something like:
Resolving the AlertmanagerReceiversNotConfigured alert firing

And in that section, explain the issue and have a link to the relevant docs for how to configure the alert receivers. This will enhance the doc experience by having the alert explicitely covered, and the users then do not have to search for the config section directly.