Fixed #21580 -- Clarified why render() does not return a TemplateResponse object.

   :func:`render_to_response()` with a ``context_instance`` argument that

   forces the use of a :class:`~django.template.RequestContext`.

   Django does not provide a shortcut function which returns a

   :class:`~django.template.response.TemplateResponse` because the constructor

   of :class:`~django.template.response.TemplateResponse` offers the same level

   of convenience as :func:`render()`.

Required arguments

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