Merge pull request #37019 from prabhakar-oracle/patch-1

Document generating SHA256 CA certificate

Author: k8s-ci-robot

content/en/docs/tasks/administer-cluster/certificates.md

@@ -140,7 +140,7 @@ manually through `easyrsa`, `openssl` or `cfssl`.
    ```shell
    openssl x509 -req -in server.csr -CA ca.crt -CAkey ca.key \
        -CAcreateserial -out server.crt -days 10000 \
-       -extensions v3_ext -extfile csr.conf
+       -extensions v3_ext -extfile csr.conf -sha256
    ```
 
 1. View the certificate signing request: