Encourage contributions in README and CONTRIBUTING

CHANGELOG.md

@@ -14,6 +14,7 @@ Code freeze date: YYYY-MM-DD
 
 ### Changed
 
+- Update `CONTRIBUTING.md` to better explain types of contributions to this repository [#797](https://github.com/CLIMADA-project/climada_python/pull/797)
 - The default tile layer in Exposures maps is not Stamen Terrain anymore, but [CartoDB Positron](https://github.com/CartoDB/basemap-styles). Affected methods are `climada.engine.Impact.plot_basemap_eai_exposure`,`climada.engine.Impact.plot_basemap_impact_exposure` and `climada.entity.Exposures.plot_basemap`. [#798](https://github.com/CLIMADA-project/climada_python/pull/798)
 
 ### Fixed

CONTRIBUTING.md

@@ -1,8 +1,26 @@
 # CLIMADA Contribution Guide
 
-Thank you for contributing to CLIMADA!
+We welcome any contribution to CLIMADA and want to express our thanks to everybody who contributes.
 
-## Overview
+## What Warrants a Contribution?
+
+Anything!
+For orientation, these are some categories of possible contributions we can think of:
+
+* **Technical problems and bugs:** Did you encounter a problem when using CLIMADA? Raise an [issue](https://github.com/CLIMADA-project/climada_python/issues) in our repository, providing a description or ideally a code replicating the error. Did you already find a solution to the problem? Please raise a pull request to help us resolve the issue!
+* **Documentation and Tutorial Updates:** Found a typo in the documentation? Is a tutorial lacking some information you find important? Simply fix a line, or add a paragraph. We are happy to incorporate you additions! Please raise a pull request!
+* **New Modules and Utility Functions:** Did you create a function or an entire module you find useful for your work? Maybe you are not the only one! Feel free to simply raise a pull request for functions that improve, e.g., plotting or data handling. As an entire module has to be carefully integrated into the framework, it might help if you talk to us first so we can design the module and plan the next steps. You can do that by raising an issue or starting a [discussion](https://github.com/CLIMADA-project/climada_python/discussions) on GitHub.
+
+A good place to start a personal discussion is our monthly CLIMADA developers call.
+Please contact the [lead developers](https://wcr.ethz.ch/research/climada.html) if you want to join.
+
+## Why Should You Contribute?
+
+* You will be listed as author of the CLIMADA repository in the [AUTHORS](AUTHORS.md) file.
+* You will improve the quality of the CLIMADA software for you and for everybody else using it.
+* You will gain insights into scientific software development.
+
+## Minimal Steps to Contribute
 
 Before you start, please have a look at our [Developer Guide][devguide].
 

README.md

@@ -61,7 +61,9 @@ Please use the following logo if you are presenting results obtained with or thr
 
 ## Contributing
 
-See the [Contribution Guide](CONTRIBUTING.md).
+We welcome any contribution to this repository, be it bugfixes and other code changes and additions, documentation improvements, or tutorial updates.
+
+If you would like to contribute, please refer to our [Contribution Guide](CONTRIBUTING.md).
 
 ## Versioning