Update README.md

Author: ipeirotis

README.md

@@ -9,7 +9,7 @@ This is a set of notes used for teaching Python to students that have never used
 ## Notes
 
 * The notes are in the form of iPython notebooks and are stored under the `/notes` folder.
-* If you are an NYU student, you can [use the NYU JupyterHub server] to access the Jupyter server and the notes (under `/notes/pi1/introduction-to-python`).
+* If you are an NYU student, you can [use the NYU JupyterHub server](https://jupyterhub.stern.nyu.edu/) to access the Jupyter server and the notes (under `/notes/pi1/introduction-to-python`).
 * If you do not have access to your own Jupyter server, you can interact with the notes by clicking the "[Launch Binder](https://mybinder.org/v2/gh/ipeirotis/introduction-to-python/master)" button.