docs: adds additional info for monitoring documentation

docs/user-guide/monitoring.md

@@ -5,3 +5,25 @@ UnderStack uses the `kube-prometheus-stack` which is a prometheus + grafana moni
 <https://github.com/prometheus-operator/kube-prometheus>
 
 It uses the namespace: `monitoring`
+
+# Accessing Prometheus
+
+Prometheus is not exposed publicly so a port-forward needs to be created
+and then you'll be able to access the Prometheus UI.
+
+```
+kubectl -n monitoring port-forward service/prometheus-operated 9090:9090
+```
+
+Once the port-forward is running, you can browse to <http://localhost:9090> to access Prometheus UI.
+
+# Accessing AlertManager
+
+AlertManager is not exposed publicly so a port-forward needs to be created
+and then you'll be able to access the AlertManager UI.
+
+```
+kubectl -n monitoring port-forward service/alertmanager-operated 9093:9093
+```
+
+Once the port-forward is running, you can browse to <http://localhost:9093> to access AlertManager UI.