Fixed #23666 -- Recommended Git Bash for running unit tests on Windows.

docs/internals/contributing/writing-code/unit-tests.txt

@@ -34,6 +34,11 @@ sample settings module that uses the SQLite database. To run the tests::
    $ cd django-repo/tests
    $ PYTHONPATH=..:$PYTHONPATH ./runtests.py
 
+.. admonition:: Windows users
+
+    We recommend something like `Git Bash <https://msysgit.github.io/>`_ to run
+    the tests using the above approach.
+
 You can avoid typing the ``PYTHONPATH`` bit each time by adding your Django
 checkout to your ``PYTHONPATH`` or by installing the source checkout using pip.
 See :ref:`installing-development-version`.