Remove setup.py

[MilyMilo]

With the introduction of pyproject.toml poetry can handle building and publishing of the packages which makes this process cleaner.

poetry build - will build the package
poetry publish - will publish the packages

No need for wheel, twine, setup.py, manifest and requirements file.

I've tested the workflow locally, but it should probably also be tested with the test-pypi repository:

• add the test-pypi repository - poetry config repositories.test-pypi https://test.pypi.org/legacy/
• add the token for test-pypi - poetry config pypi-token.test-pypi <token>
• publish the package - poetry publish -r test-pypi

I've also added an entrypoint script so that it can be installed with pipx which is really neat: https://pipxproject.github.io/