DOC: how to contribute to doc

README_SETUP.md

@@ -109,6 +109,8 @@ Now would be a good time to continue with the [tutorials](tutorials/index).
 - Run a specific test function: e.g. `tox -- unittests/test_schema.py::test_config_files`
 
 ## Documentation ##
+We use sphinx to create the documentation. Docstrings in the code should comply
+with the Googly style (see link below).
 
 Build documentation in `build/` with `make doc`.
 
@@ -118,5 +120,11 @@ Build documentation in `build/` with `make doc`.
 - `sphinx-autoapi`
 - `recommonmark`
 
+### How to contribute ###
+
+- [Google Style Python Docstrings](https://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html)
+- [Google Style Python Docstrings 2nd reference](https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings)
+- [References to other documentation](https://www.sphinx-doc.org/en/master/usage/extensions/intersphinx.html#role-external)
+
 ### Troubleshooting ###
 If the client is to be executed directly from the `/src` folder, an initial `.\setup.py install --user` must be called.