Add install instructions

README.rst

@@ -6,6 +6,10 @@ Python framework to train neural networks in the context of high-energy physics.
 The framework also provides convenient methods to create the typical plots. The
 dataset is assumed to be stored in a dataframe.
 
+.. code:: console
+
+  pip install https://gitlab.cern.ch/fsauerbu/freeforestml/-/archive/master/freeforestml-master.zip
+
 Links
 =====
 

docs/index.rst

@@ -19,6 +19,10 @@ Python framework to train neural networks in the context of high-energy physics.
 The framework also provides convenient methods to create the typical plots. The
 dataset is assumed to be stored in a dataframe.
 
+.. code:: console
+
+  pip install https://gitlab.cern.ch/fsauerbu/freeforestml/-/archive/master/freeforestml-master.zip
+
 Links
 =====