update contributors

Author: Kristian Rother

README.md

@@ -523,7 +523,7 @@ course, you may only interrupt your own programs, not those owned by
 
 ### License
 
-**© 2010 Dr. Kristian Rother**
+**© 2024 Dr. Kristian Rother**
 
 This tutorial is published under the Creative Commons Attribution
 Share-alike License 4.0
@@ -533,6 +533,8 @@ You can find the full sources on
 
 ### Acknowledgements
 
+Thanks to many students for using the tutorial in practice and finding bugs. Thanks to `@zulcas` for contributing bugfixes.
+
 I thank Janusz M. Bujnicki, Allegra Via, Pedro Fernandes and Joachim
 Jacob for their help with testing and reviewing the material. Further
 thanks go to the German Academic Exchange Service (DAAD) for financial