The exception used when a template does not exist. Optional arguments:
- backend
- The template backend class used when raising this exception.
- tried
- A list of sources that were tried when finding the template. This
is formatted as a list of tuples containing (origin, status), where
origin is an Origin object or duck type and status is a string with the
reason the template wasn't found.
- chain
- A list of intermediate TemplateDoesNotExist exceptions. This is used to
encapsulate multiple exceptions when loading templates from multiple
engines.