small corrections to jupyterhub instructions

content/mm16.rst

@@ -10,13 +10,16 @@ This page collects materials for the APS March meeting 2016 tutorial `“Introdu
 Interactive Computing
 =====================
 During the tutorial there will be a computing environment available for
-participants to use to follow along with the demonstrations.  Log-in
-information will be distributed at the start of the session.  Depending on the
-"hub" to which you have been assigned you should log in here: 
+participants to follow along with the demonstrations.  Login information will
+be distributed at the start of the session.  You can use one of the following
+links (depending on the "hub" to which you have been assigned) to take you to
+the login page:
 
 * `hub 1 <https://mm16.kwant-project.org/hub1>`_
 * `hub 2 <https://mm16.kwant-project.org/hub2>`_
 * `hub 3 <https://mm16.kwant-project.org/hub3>`_
 
-If you wish to save anything onto your local machine you can do so by going to
-the `file` menu, selecting `download as` and choosing the download format.
+Any files saved into the environment will be deleted after the tutorial has
+finished.  If you wish to save anything onto your local machine, you can do so
+by going to the `file` menu, selecting `download as` and choosing the download
+format.