Request: Add `requirements.txt` to Pypi manifest and/or tags for each release.

[kacper-uminski]

Hi!

The current Pypi package does not include a requirements.txt in the provided tarball (here). This makes it impossible to build using some meta-build-systems, such as nix, without fetching directly from github. This would not be a problem if the Github had tags for each release, but it does not. Would it be possible to add either of these two things? If you point me in the right direction, I may be able to make an MR myself. Any help would be appreciated! :)

Best regards,
Kacper