Fixed formatting for markdown file (#12192)

* Fixed formatting for markdown file

File updated: define-environment-variable-container.md
Language: zh

* Fixes to markdown formatting

content/zh/docs/tasks/inject-data-application/define-environment-variable-container.md

@@ -30,32 +30,44 @@ content_template: templates/task
 
 1. 基于YAML文件创建一个Pod:
 
+    ```shell
     kubectl create -f https://k8s.io/docs/tasks/inject-data-application/envars.yaml
+    ```
 
 1. 获取一下当前正在运行的Pods信息:
 
+    ```shell
     kubectl get pods -l purpose=demonstrate-envars
+    ```
 
     查询结果应为:
 
+    ```log
     NAME            READY     STATUS    RESTARTS   AGE
     envar-demo      1/1       Running   0          9s
+    ```
 
 1. 进入该Pod下的容器并打开一个命令终端:
 
+    ```shell
     kubectl exec -it envar-demo -- /bin/bash
+    ```
 
 1. 在命令终端中通过执行`printenv`打印出环境变量。
 
+    ```shell
     root@envar-demo:/# printenv
+    ```
 
     打印结果应为:
 
+    ```log
     NODE_VERSION=4.4.2
     EXAMPLE_SERVICE_PORT_8080_TCP_ADDR=10.3.245.237
     HOSTNAME=envar-demo
     ...
     DEMO_GREETING=Hello from the environment
+    ```
 
 1. 通过键入`exit`退出命令终端。
 

content/zh/docs/tasks/inject-data-application/distribute-credentials-secure.md

@@ -201,5 +201,3 @@ base-64 形式的密码为 `Mzk1MjgkdmRnN0pi`。
 * [Pod](/docs/api-reference/{{< param "version" >}}/#pod-v1-core)
 
 {{% /capture %}}
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