Update copyright statement

Author: juho05

README.md

@@ -6,7 +6,7 @@ The Go module for [codegame-cli](https://github.com/code-game-project/codegame-c
 
 ## License
 
-Copyright (c) 2022 CodeGame Contributors (https://code-game.org/contributors)
+Copyright (c) 2022 Julian Hofmann
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by