link fixed

Link to `100 Numpy exercises.md` fixed

Author: denkorzh

README.md

@@ -9,7 +9,7 @@ reference for both old and new users but also to provide a set of exercices for
 those who teach.
 
 → [Test them on Binder](http://mybinder.org:/repo/rougier/numpy-100/notebooks/100%20Numpy%20exercises.ipynb)  
-→ [Read them on GitHub](100 Numpy exercises.md)  
+→ [Read them on GitHub](100%20Numpy%20exercises.md)  
 
 This work is licensed under a MIT license.  
 [![DOI](https://zenodo.org/badge/10173/rougier/numpy-100.svg)](https://zenodo.org/badge/latestdoi/10173/rougier/numpy-100)