Merge pull request #1642 from neogopher/docs-observability-isolated-mode

docs: suggest required helm values for scraping kubelet targets in Isolated mode

docs/pages/o11y/metrics/monitoring_vcluster.mdx

@@ -9,6 +9,10 @@ vCluster is able to rewrite node stats and metrics. This means monitoring a vClu
 You need to make sure that vCluster has access to the host clusters nodes. [Enabling real nodes synchronization](../../architecture/nodes.mdx) will create the required RBAC permissions.
 :::
 
+:::info
+If [Isolated mode](../../security/isolated-mode.mdx) is enabled and you wish to scrape kubelet targets via '/metrics' and '/metrics/cadvisor', you need to set `isolation.nodeProxyPermission.enabled: true`. This will create the RBAC rules for the required 'nodes/proxy' resource.
+:::
+
 Please follow the [official Kubernetes documentation](https://kubernetes.io/docs/tasks/debug-application-cluster/resource-usage-monitoring/) on how to monitor a Kubernetes cluster.
 
 ### How does it work?