Update README.md

Author: pascalwengerter

docs/contribute/README.md

@@ -9,6 +9,11 @@ If you want to contribute and are unsure what to work on, take a look at the [op
 
 Other case: You plan to built something that you think should be part of the Matestack UI Core (or you have already built it)? Great, then open a pull request and we will take a look!
 
+## How to contribute
+
+Please create a pull request to the `develop` branch with your tested and documented code. Bonus points for using our PR template!
+
+
 ## Documentation
 
 Documentation can be found in the `/docs` folder. Please make sure to cover basic use cases of your concepts & components for other users!