[receiver/kubeletstats] Add RBAC docs (open-telemetry#27655)

receiver/kubeletstatsreceiver/README.md

@@ -228,3 +228,24 @@ The following parameters can also be specified:
 
 The full list of settings exposed for this receiver are documented [here](./config.go)
 with detailed sample configurations [here](./testdata/config.yaml).
+
+### Role-based access control
+
+The Kubelet Stats Receiver needs `get` permissions on the `nodes/stats` resources. Additionally, when using `extra_metadata_labels` or any of the `{request|limit}_utilization` metrics the processor also needs `get` permissions for `nodes/proxy` resources.
+
+```yaml
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: otel-collector
+rules:
+  - apiGroups: [""]
+    resources: ["nodes/stats"]
+    verbs: ["get"]
+    
+  # Only needed if you are using extra_metadata_labels or
+  # are collecting the request/limit utilization metrics
+  - apiGroups: [""]
+    resources: ["nodes/proxy"]
+    verbs: ["get"]
+```