Update readme

README.rst

@@ -10,3 +10,25 @@ KM3NeT TestData
 .. image:: https://examples.pages.km3net.de/km3badges/docs-latest-brightgreen.svg
     :target: https://km3py.pages.km3net.de/km3net_testdata
 
+
+A package to get access to KM3NeT sample files for testing and development
+purposes.
+
+Installation and usage
+----------------------
+
+    pip install km3net_testdata
+
+The file paths can be access in Python scripts using the ``data_path()`` function:
+
+.. code-block:: python
+
+    from km3net_testdata import data_path()
+
+    filename = data_path("km3net_offline.root")
+
+
+Acknowledgements
+----------------
+
+The project idea and implementation were inspired by the Scikit-HEP Project https://github.com/scikit-hep/scikit-hep-testdata