Update ssh-keys.md

docs.it4i/general/accessing-the-clusters/shell-access-and-data-transfer/ssh-keys.md

@@ -5,7 +5,7 @@
 To generate a new keypair of your public and private key, use the `ssh-keygen` tool:
 
 ```console
-local $ ssh-keygen -C 'username@organization.example.com' -f additional_key
+local $ ssh-keygen -t ed25519 -C username@organization.example.com' -f additional_key
 ```
 
 !!! note