Update docs/book/src/tasks/bootstrap/kubeadm-bootstrap/kubelet-config.md

Co-authored-by: Fabrizio Pandini <fabrizio.pandini@gmail.com>

docs/book/src/tasks/bootstrap/kubeadm-bootstrap/kubelet-config.md

@@ -250,7 +250,7 @@ spec:
 
 We can use kubeadm's `kubeletconfiguration` patch target to patch the kubelet configuration file. In this example, we put a patch file for `kubeletconfiguration` target in `strategic` `patchtype` on nodes via `KubeadmConfigSpec.files`. For more details, see [Customizing components with the kubeadm API | Kubernetes](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/control-plane-flags/#patches)
 
-This method is useful when you want to change the kubelet configuration file partially on specific nodes. For example, you can deploy a partially patched kubelet configuration file on specific nodes based on the default configuration used for `kubeadm init`.
+This method is useful when you want to change the kubelet configuration file partially on specific nodes. For example, you can deploy a partially patched kubelet configuration file on specific nodes based on the default configuration used for `kubeadm init` or `kubeadm join`.
 
 ### KubeadmControlPlaneTemplate