Update configure kubeconfig credentials section.

README.md

@@ -100,7 +100,7 @@ kubectl proxy
 
 http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/overview?namespace=default
 
-### 配置 kubeconfig
+### 配置 kubeconfig (可选)
 
 ```bash
 $ TOKEN=$(kubectl -n kube-system describe secret default| awk '$1=="token:"{print $2}')

README_en.md

@@ -108,7 +108,7 @@ $ TOKEN=$(kubectl -n kube-system describe secret default| awk '$1=="token:"{prin
 kubectl config set-credentials docker-for-desktop --token="${TOKEN}"
 ```
 
-#### Choose kubeconfig file
+#### Choose kubeconfig file (Optional)
 
 ![resource](images/k8s_credentials.png)