Add namespaces for 1.17 + default namespace

Each Node has an associated Lease object in the kube-node-lease namespace. Lease is a lightweight resource, which improves the performance of the node heartbeats as the cluster scales.

Author: Melony QIN

content/en/docs/concepts/overview/working-with-objects/namespaces.md

@@ -55,6 +55,7 @@ NAME          STATUS    AGE
 default       Active    1d
 kube-system   Active    1d
 kube-public   Active    1d
+kube-node-lease Active 1d
 ```
 
 Kubernetes starts with three initial namespaces: