update README

Author: herry13

README.md

@@ -2,6 +2,7 @@
 
 This is a cookiecutter template of Python project that uses:
 
+- [poetry](https://python-poetry.org) for dependency management and packaging
 - [mypy](https://mypy.readthedocs.io) for type checking
 - [pylint](https://pylint.readthedocs.io) for linting
 - [isort](https://pycqa.github.io/isort/) and [black](https://github.com/psf/black) for code formatting