Merge pull request #38010 from Shubham82/Add_shell

Append triple backticks with shell for code snippet

Author: k8s-ci-robot

content/en/docs/reference/access-authn-authz/certificate-signing-requests.md

@@ -268,7 +268,7 @@ The certificate value is in Base64-encoded format under `status.certificate`.
 
 Export the issued certificate from the CertificateSigningRequest.
 
-```
+```shell
 kubectl get csr myuser -o jsonpath='{.status.certificate}'| base64 -d > myuser.crt
 ```
 
@@ -295,20 +295,20 @@ The last step is to add this user into the kubeconfig file.
 
 First, you need to add new credentials:
 
-```
+```shell
 kubectl config set-credentials myuser --client-key=myuser.key --client-certificate=myuser.crt --embed-certs=true
 
 ```
 
 Then, you need to add the context:
 
-```
+```shell
 kubectl config set-context myuser --cluster=kubernetes --user=myuser
 ```
 
 To test it, change the context to `myuser`:
 
-```
+```shell
 kubectl config use-context myuser
 ```