Added docs for running a client and a dedicated server on same machine

diff --git a/server/readme.txt b/server/readme.txt
index 7c71d6173d624387a1e29341504239175d0a35b0..5bc028010488bc6e27596c804730251424676a7d 100644 (file)
--- a/server/readme.txt
+++ b/server/readme.txt
@@ -19,6 +19,13 @@ in your server.cfg for the right port number, default is 26000) to the
 computer running your server.  How to do this does depend on your\r
 computer and network setup.\r
 \r
+If you want to run a dedicated server and a client on the the same\r
+machine, they need to have session ids that differ from each other.\r
+To start the server with a custom session id (different from the\r
+default id that the client uses) run it with the argument "-sessionid"\r
+followed by a session id of your choice.\r
+Example: server_linux.sh -sessionid server\r
+\r
 If you plan to install custom maps on your server you should read the\r
 file Xonotic/Docs/mapdownload.txt to learn how to setup automatic map\r
 downloads.\r