Updated readme

README.md

@@ -37,6 +37,15 @@ West Side Diner:     westside
 Mensa Hochschule:    hochschule
 ```
 
+## Contributing
+
+1. Fork it
+2. Create a feature branch with a meaningful name (`git checkout -b my-new-feature`)
+3. Add yourself to the CONTRIBUTORS file
+4. Commit your changes (`git commit -am 'Add some feature'`)
+5. Push to your branch (`git push origin my-new-feature`)
+6. Create a new pull request
+
 ## Credits
 Thanks a lot at [Thomas Lukaseder](https://github.com/seder) and his [Mensaplan Parser](https://github.com/seder/mensaplan-parser).