Updated readme with contribution

Author: LoosC

README.md

@@ -1,5 +1,7 @@
 # Benchmark Problems for Dynamic Modeling of Intracellular Processes
-A collection of ODE models with experimental data as benchmark problems in order to evaluate new and existing methodologies for data-based modelling
+A collection of ODE models with experimental data as benchmark problems in order to evaluate new and existing methodologies for data-based modeling.
 
 The benchmark models were export from Data2Dynamics (https://github.com/Data2Dynamics/d2d), version of Aug 17th 2018, commit tag f27f9fd554fd23f9c048239172fafc6686a27fe0.
 Export can be repeated by compiling the respective model within the 'Example' folder, followed by call of 'arExportBenchmark'
+
+Contributions to the collection are very welcome. For this, please fork the repository, add your model and test your files with the provided functions, and start a pull request. We will then check your model and merge it into the collection. We are continuously working on the extension of the collection.