Update working-with-ssh-key-passphrases.md (#2188)

* Update working-with-ssh-key-passphrases.md

This is a follow-up on https://github.com/github/docs/issues/876#issue-731279207 to address another article affected.
Changes proposed are to align with the article "Generating a new SSH key and adding it to the ssh-agent".

* Update content/github/authenticating-to-github/working-with-ssh-key-passphrases.md

* Update content/github/authenticating-to-github/working-with-ssh-key-passphrases.md

* Update content/github/authenticating-to-github/working-with-ssh-key-passphrases.md

* Update content/github/authenticating-to-github/working-with-ssh-key-passphrases.md

Co-authored-by: hubwriter <hubwriter@github.com>

content/github/authenticating-to-github/working-with-ssh-key-passphrases.md

@@ -18,12 +18,11 @@ With SSH keys, if someone gains access to your computer, they also gain access t
 You can change the passphrase for an existing private key without regenerating the keypair by typing the following command:
 
 ```shell
-$ ssh-keygen -p
-# Start the SSH key creation process
-> Enter file in which the key is (/Users/<em>you</em>/.ssh/id_rsa): <em>[Hit enter]</em>
-> Key has comment '/Users/<em>you</em>/.ssh/id_rsa'
+$ ssh-keygen -p -f ~/.ssh/id_ed25519
+> Enter old passphrase: <em>[Type old passphrase]</em>
+> Key has comment '<em>your_email@example.com</em>'
 > Enter new passphrase (empty for no passphrase): <em>[Type new passphrase]</em>
-> Enter same passphrase again: <em>[One more time for luck]</em>
+> Enter same passphrase again: <em>[Repeat the new passphrase]</em>
 > Your identification has been saved with the new passphrase.
 ```