add kube-node-lease namespace

keep pace with https://github.com/kubernetes/website/blob/main/content/en/docs/concepts/overview/working-with-objects/namespaces.md

Author: donhui

content/en/docs/tasks/administer-cluster/namespaces.md

@@ -28,20 +28,22 @@ List the current namespaces in a cluster using:
 kubectl get namespaces
 ```
 ```console
-NAME          STATUS    AGE
-default       Active    11d
-kube-system   Active    11d
-kube-public   Active    11d
+NAME              STATUS   AGE
+default           Active   11d
+kube-node-lease   Active   11d
+kube-public       Active   11d
+kube-system       Active   11d
 ```
 
-Kubernetes starts with three initial namespaces:
+Kubernetes starts with four initial namespaces:
 
 * `default` The default namespace for objects with no other namespace
-* `kube-system` The namespace for objects created by the Kubernetes system
+* `kube-node-lease` This namespace holds [Lease](/docs/concepts/architecture/leases/) objects associated with each node. Node leases allow the kubelet to send [heartbeats](/docs/concepts/architecture/nodes/#heartbeats) so that the control plane can detect node failure.
 * `kube-public` This namespace is created automatically and is readable by all users
   (including those not authenticated). This namespace is mostly reserved for cluster usage,
   in case that some resources should be visible and readable publicly throughout the whole cluster.
   The public aspect of this namespace is only a convention, not a requirement.
+* `kube-system` The namespace for objects created by the Kubernetes system
 
 You can also get the summary of a specific namespace using: