Add a note about superuser status. #914.

docs/users.rst

@@ -13,6 +13,10 @@ Replace ``localhost:8000`` with your PANDA's domain name.
 
 In the upper-right corner click "Add user". Type in the email address and name and click "Save". If you've already setup :doc:`Email <email>` then you will receive a registration email with an activation link. Ignore it. On the details page for your new user click the "change password form" link underneath the **Password** field. Enter your password and click "Change Password". Check the **Active**, **Staff status** and **Superuser status** checkboxes and click "Save".
 
+.. note::
+
+    You must enable **Superuser status** in order for the new user to be able to use the admin. Staff-only users will be ableto login to the admin, but will not have permission to view or edit any configuration.
+
 Creating new PANDA users
 ========================