[nWT] Migration to puffer.fish

As of today, we moved the core of the project to the puffer.fish infrastructure.

The official channel for communication and development of nc0’s Web Toolkit is this mailing nwt@puffer.fish. The canonical and publicly available tree for the project (outside of my local fork) is the one available at https://git.puffer.fish/nico/web.git.

— nc0 (https://nc0.fr/pgp)