DOC: info on contribution

README.md

-# Welcome
+# README
+
+## Welcome
 
 This is the **CaosDB Python Client Library** repository and a part of the
 CaosDB project.
 
-# Setup
+## Setup
 
 Please read the [README_SETUP.md](README_SETUP.md) for instructions on how to
 setup this code.
 
 
-# Further Reading
+## Further Reading
 
 Please refer to the [official gitlab repository of the CaosDB
 project](https://gitlab.com/caosdb/caosdb) for more information.
 
-# License
+## Contributing
+
+Thank you very much to all contributers—[past, present](https://gitlab.com/caosdb/caosdb/-/blob/dev/HUMANS.md), and prospective ones.
+
+### Code of Conduct
+
+By participating, you are expected to uphold our [Code of Conduct](https://gitlab.com/caosdb/caosdb/-/blob/dev/CODE_OF_CONDUCT.md).
+
+### How to Contribute
+
+* You found a bug, have a question, or want to request a feature? Please 
+[create an issue](https://gitlab.com/caosdb/caosdb-pylib/-/issues).
+* You want to contribute code? Please fork the repository and create a merge 
+request in GitLab and choose this repository as target. Make sure to select
+"Allow commits from members who can merge the target branch" under Contribution
+when creating the merge request. This allows our team to work with you on your request.
+- If you have a suggestion for the [documentation](https://caosdb.gitlab.io/caosdb-pylib/), 
+the preferred way is also a merge request as describe above (the documentation resides in `src/doc`).
+However, you can also create an issue for it. 
+- You can also contact us at **info (AT) caosdb.de**.
+
+## License
 
 * Copyright (C) 2018 Research Group Biomedical Physics, Max Planck Institute
   for Dynamics and Self-Organization Göttingen.
@@ -22,4 +45,3 @@ project](https://gitlab.com/caosdb/caosdb) for more information.
 
 All files in this repository are licensed under a [GNU Affero General Public
 License](LICENCE.md) (version 3 or later).
-