README: added SHA256 fingerprint (#182)

Author: jericbryledy

README.md

@@ -14,7 +14,7 @@ Join the party:
 $ ssh chat.shazow.net
 ```
 
-The server's RSA key fingerprint is `e5:d5:d1:75:90:38:42:f6:c7:03:d7:d0:56:7d:6a:db`. If you see something different, you might be [MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack)'d.
+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.
 
 (Apologies if the server is down, try again shortly.)