Fixed #20417 - Noted that a server restart is required to load new templatetag modules.

The app should contain a ``templatetags`` directory, at the same level as

``models.py``, ``views.py``, etc. If this doesn't already exist, create it -

don't forget the ``__init__.py`` file to ensure the directory is treated as a

Python package.

Python package. After adding this module, you will need to restart your server

before you can use the tags or filters in templates.

Your custom tags and filters will live in a module inside the ``templatetags``

directory. The name of the module file is the name you'll use to load the tags