Update HAProxy Config Docs

Add explanation / config example for HAProxy on how to proxy Telnet through it, so Secure Telnet can be used instead of just regular telnet.

docs/source/Setup/Config-HAProxy.md

@@ -157,6 +157,8 @@ We use the `my.awesomegame.com` example here and here are the ports
 - `4001` is the standard Evennia webserver port (firewall closed!)
 - `4002` is the default Evennia websocket port (we use the same number for
   the outgoing wss port, so this should be open in firewall).
+- `4000` is the default Telnet port for Evennia, and we proxy through HAProxy
+  so `7000` can used for Secure Telnet connections instead.
 
 ```shell
 # base stuff to set up haproxy
@@ -187,6 +189,14 @@ listen evennia-secure-websocket
     timeout server 10m
     timeout connect 5m
 
+listen evennia-secure-telnet
+    bind my.awesomegame.com:7000 ssl no-sslv3 no-tlsv10 crt /etc/letsencrypt/live/my.awesomegame.com/my.awesomegame.com.pem
+    server localhost 127.0.0.1:4000
+    mode tcp
+    timeout client 10m
+    timeout server 10m
+    timeout connect 5m
+
 ```
 
 ## Putting it all together