Update ssh.chat pubkey

Author: shazow

README.md

@@ -18,7 +18,9 @@ $ ssh ssh.chat
 
 Please abide by our [project's Code of Conduct](https://github.com/shazow/ssh-chat/blob/master/CODE_OF_CONDUCT.md) while participating in chat.
 
-The server's RSA key fingerprint is `MD5:e5:d5:d1:75:90:38:42:f6:c7:03:d7:d0:56:7d:6a:db` or `SHA256:HQDLlZsXL3t0lV5CHM0OXeZ5O6PcfHuzkS8cRbbTLBI`. If you see something different, you might be [MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack)'d.
+The host's public key is `ssh.chat ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKPrQofxXqoz2y9A7NFkkENt6iW8/mvpfes3RY/41Oyt` and the fingerprint is `SHA256:yoqMXkCysMTBsvhu2yRoMUl+EmZKlvkN+ZKmL3115xU` (as of 2021-10-13).
+
+If you see something different, you might be [MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack)'d.
 
 (Apologies if the server is down, try again shortly.)