Update kustomization.md

command: ["start", "--host", "\$(MY_SERVICE_NAME)"]
The back slash causes an error. So removed it.
The error detail below
```
Error: rawResources failed to read Resources: YAML file [deployment.yaml] encounters a format error.
error converting YAML to JSON: yaml: line 18: found unknown escape character
```
```
kubectl version
Client Version: version.Info{Major:"1", Minor:"19", GitVersion:"v1.19.3", GitCommit:"1e11e4a2108024935ecfcb2912226cedeafd99df", GitTreeState:"clean", BuildDate:"2020-10-14T12:50:19Z", GoVersion:"go1.15.2", Compiler:"gc", Platform:"windows/amd64"}
Server Version: version.Info{Major:"1", Minor:"19", GitVersion:"v1.19.3", GitCommit:"1e11e4a2108024935ecfcb2912226cedeafd99df", GitTreeState:"clean", BuildDate:"2020-10-14T12:41:49Z", GoVersion:"go1.15.2", Compiler:"gc", Platform:"linux/amd64"}
```

content/en/docs/tasks/manage-kubernetes-objects/kustomization.md

@@ -590,7 +590,7 @@ spec:
       containers:
       - name: my-nginx
         image: nginx
-        command: ["start", "--host", "\$(MY_SERVICE_NAME)"]
+        command: ["start", "--host", "$(MY_SERVICE_NAME)"]
 EOF
 
 # Create a service.yaml file