Update README.rst (scikit-learn-contrib#223)

* Update README.rst

* Update README.rst

* Update README.rst

Author: rosecers

README.rst

@@ -82,6 +82,16 @@ Writing code is not the only way to contribute to the project. You can also:
 
 .. marker-contributors
 
+Citing scikit-matter
+--------------------
+
+If you use scikit-matter for your work, please cite:
+
+Goscinski A, Principe VP, Fraux G et al. scikit-matter :
+A Suite of Generalisable Machine Learning Methods Born out of Chemistry
+and Materials Science. Open Res Europe 2023, 3:81.
+`10.12688/openreseurope.15789.2 <https://doi.org/10.12688/openreseurope.15789.2>`_
+
 Contributors
 ------------