Promote the Tox container image

[encukou]

Lumír is building a Docker image that has Fedora, Tox and all the Pythons.
We should promote that more.
Possibly turn it into a GitHub Action and write a Magazine article about it?

[hroncok]

https://github.com/fedora-python/fedora-python-tox

[hroncok]

When preparing my EuroPython lightning talk, I've talked about the github action and I realized it's not mentioned on fedoralovespython.org yet. We should do that.