feat: Adds link to license in readme

Would resolve scikit-learn-contrib#261 if merged

Author: darigovresearch

README.rst

@@ -516,7 +516,11 @@ Below example shows how to change logging level.
 
     >>> import logging
     >>> logging.getLogger('sklearn_pandas').setLevel(logging.INFO)
-    
+
+License
+-------
+For more details on the license of this repository see [License](https://github.com/scikit-learn-contrib/sklearn-pandas/blob/master/LICENSE).
+
 
 Changelog
 ---------
@@ -669,6 +673,7 @@ Changelog
 * Allow specifying a list of transformers to use sequentially on the same column.
 
 
+
 Credits
 -------