Use kubectl config current-context to simplify the instructions

docs/user-guide/namespaces.md

@@ -64,16 +64,8 @@ $ kubectl --namespace=<insert-namespace-name-here> get pods
 You can permanently save the namespace for all subsequent kubectl commands in that
 context.
 
-First get your current context:
-
 ```shell
-$ export CONTEXT=$(kubectl config view | awk '/current-context/ {print $2}')
-```
-
-Then update the default namespace:
-
-```shell
-$ kubectl config set-context $CONTEXT --namespace=<insert-namespace-name-here>
+$ kubectl config set-context $(kubectl config current-context) --namespace=<insert-namespace-name-here>
 # Validate it
 $ kubectl config view | grep namespace:
 ```