Add support for django models

[mRokita]

Is your feature request related to a problem? Please describe.
It would be nice to be able to document Django models without adding docstrings, just like pydantic models.

Describe the solution you'd like
Add similar support for Django models

Describe alternatives you've considered
Adding docstrings to every model field, I don't really like it because usually it means duplicating verbose_name value.

[pawamoy]

Approved!

Don't expect it soon though, I have little time these days to work on FOSS 🙂
However I'll always have time to review PRs if you want to send some 😉

[pawamoy]

Also, transfering over to pytkdocs.

[pawamoy]

(basic?) Support added for Django models in #101