NET-4804: Add dashboard for monitoring consul-k8s (#18208)

grafana/README.md

@@ -9,3 +9,7 @@ The page for publishing this dashboard is https://grafana.com/grafana/dashboards
     - Click "share" and export for external publishing
     - Login to Grafana via the team account (message a manager)
     - Publish as a new version, including change notes.
+
+### Grafana dashboard for consul-k8s (control plane)
+
+A grafana dashboard for monitoring consul-k8s (control plane) can also be found in this directory: `consul-k8s-control-plane-monitoring.json`. This dashboard has not been published to https://grafana.com.