[1.4.x] Fixed #21195 -- Clarifed usage of template_name in tutorial part 4.

By default, the :class:`~django.views.generic.list.DetailView` generic

view uses a template called ``<app name>/<model name>_detail.html``.

In our case, it'll use the template ``"polls/poll_detail.html"``. The

In our case, it would use the template ``"polls/poll_detail.html"``. The

``template_name`` argument is used to tell Django to use a specific

template name instead of the autogenerated default template name. We

also specify the ``template_name`` for the ``results`` list view --