Incorrect poetry link in PyPI project descripion

[stprior]

The link for Poetry in the Install section on https://pypi.org/project/py2puml/ goes to https://pipenv.readthedocs.io/en/latest/ rather than https://python-poetry.org/.

[lucsorel]

hi @stprior,

Thank you for noticing this typo. I will fix this in the next release.