User contributed addons

[georgepar]

Hi,

First of all thank you for this awesome project.
I have created a stringifier for integrating pudb + pytorch to debug ML code, and
I am wondering if there is a contrib folder / side-project for user contributed themes / stringifiers.

I would find it very interesting if such a platform was created to allow users to share domain specific customizations.

[inducer]

Feel free to make a PR that adds a contrib folder and adds this there. Make sure to make a subdirectory with a README, and feel free to add a link to the root README for visibility.