[1.5.x] Added some text I meant to add in the last commit.
Backport of 2699219 from master
|@@ -50,7 +50,7 @@ Once you're ready, it is time to :doc:`install the new Django version|
|might want to set up a new environment will all the dependencies first.|
|Exactly which steps you will need to take depends on your installation process.|
|-The most convenient way is to use pip_:|
|+The most convenient way is to use pip_ with the ``--upgrade`` or ``-U`` flag:|
|.. code-block:: bash|