[zh]Update kubectl installation instructions for Linux

Signed-off-by: ydFu <ader.ydfu@gmail.com>

content/zh-cn/docs/tasks/tools/install-kubectl-linux.md

@@ -98,12 +98,12 @@ The following methods exist for installing kubectl on Linux:
 
    下载 kubectl 校验和文件：
 
-   {{< tabs name="download_checksum_linux" >}} 
+   {{< tabs name="download_checksum_linux" >}}
    {{< tab name="x86-64" codelang="bash" >}}
-   curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"
+   curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"
    {{< /tab >}}
    {{< tab name="ARM64" codelang="bash" >}}
-   curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/arm64/kubectl.sha256"
+   curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/arm64/kubectl.sha256"
    {{< /tab >}}
    {{< /tabs >}}
 
@@ -225,6 +225,7 @@ Or use this for detailed view of version:
    # 如果 `/etc/apt/keyrings` 目录不存在，则应在 curl 命令之前创建它，请阅读下面的注释。
    # sudo mkdir -p -m 755 /etc/apt/keyrings
    curl -fsSL https://pkgs.k8s.io/core:/stable:/{{< param "version" >}}/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
+   sudo chmod 644 /etc/apt/keyrings/kubernetes-apt-keyring.gpg # allow unprivileged APT programs to read this keyring   
    ```
 
 {{< note >}}
@@ -246,23 +247,22 @@ In releases older than Debian 12 and Ubuntu 22.04, folder `/etc/apt/keyrings` do
    ```shell
    # This overwrites any existing configuration in /etc/apt/sources.list.d/kubernetes.list
    echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/{{< param "version" >}}/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
+   sudo chmod 644 /etc/apt/sources.list.d/kubernetes.list   # helps tools such as command-not-found to work correctly
    ```
    -->
    ```shell
    # 这会覆盖 /etc/apt/sources.list.d/kubernetes.list 中的所有现存配置
    echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/{{< param "version" >}}/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
+   sudo chmod 644 /etc/apt/sources.list.d/kubernetes.list   # 有助于让诸如 command-not-found 等工具正常工作
    ```
 
 {{< note >}}
-   <!--
-   To upgrade kubectl to another minor release, you'll need to bump the version in
-   `/etc/apt/sources.list.d/kubernetes.list` before running `apt-get update` and
-   `apt-get upgrade`. This procedure is described in more detail in
-   [Changing The Kubernetes Package Repository](/docs/tasks/administer-cluster/kubeadm/change-package-repository/).
-   -->
-要升级 kubectl 到别的次要版本，你需要先升级 `/etc/apt/sources.list.d/kubernetes.list` 中的版本，
-再运行 `apt-get update` 和 `apt-get upgrade`。
-更详细的步骤可以在[更改 Kubernetes 软件包仓库](/zh-cn/docs/tasks/administer-cluster/kubeadm/change-package-repository/)中找到。
+<!--
+To upgrade kubectl to another minor release, you'll need to bump the version in `/etc/apt/sources.list.d/kubernetes.list` before running `apt-get update` and `apt-get upgrade`. This procedure is described in more detail in [Changing The Kubernetes Package Repository](/docs/tasks/administer-cluster/kubeadm/change-package-repository/).
+ -->
+要将 kubectl 升级到别的次要版本，你需要先升级 `/etc/apt/sources.list.d/kubernetes.list` 中的版本，
+再运行 `apt-get update` 和 `apt-get upgrade` 命令。
+更详细的步骤可以在[更改 Kubernetes 软件包存储库](/zh-cn/docs/tasks/administer-cluster/kubeadm/change-package-repository/)中找到。
 {{< /note >}}
 
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