Added link to sf's Shell Service Instruction page for developers.

Author: bernhardreiter

doc/developers.txt

@@ -26,6 +26,7 @@ Website, wiki
 -------------
 
 1. ssh -t <username>,[email protected] create
+   Docs: http://sourceforge.net/apps/trac/sourceforge/wiki/Shell%20service
 2. cd /home/groups/r/ro/roundup
 3. follow instructions in README.txt