Merge pull request #27416 from joostas/docker-cli-to-kubectl-ko

[ko] Fix label selector in "kubectl for Docker Users"

Author: k8s-ci-robot

content/ko/docs/reference/kubectl/docker-cli-to-kubectl.md

@@ -265,7 +265,7 @@ nginx-app    1/1     1            1           2m
 ```
 
 ```shell
-kubectl get po -l run=nginx-app
+kubectl get po -l app=nginx-app
 ```
 ```
 NAME                         READY     STATUS    RESTARTS   AGE
@@ -279,7 +279,7 @@ deployment "nginx-app" deleted
 ```
 
 ```shell
-kubectl get po -l run=nginx-app
+kubectl get po -l app=nginx-app
 # 아무것도 반환하지 않는다
 ```