DOC: how to contribute to doc

README_SETUP.md

@@ -52,6 +52,8 @@ Optional h5-crawler:
 `make style`
 
 ## 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`.
 
@@ -60,3 +62,9 @@ Build documentation in `build/` with `make doc`.
 - `sphinx`
 - `sphinx-autoapi`
 - `recommonmark >= 0.6.0`
+
+### 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)