Ready-to-use setup.cfg file (see this gist: https://gist.github.com/corentinbettiol/2753cbc422717dc5954fe650bde9e6c4)

setup.cfg

[metadata]
name = djangocms-plugin
version = 0.0.1
description = # ADD YOUR DESCRIPTION HERE
long_description = file: README.md
long_description_content_type = text/markdown
url = # PUT YOUR REPO URL HERE
author = # PUT YOUR NAME HERE
author_email = # ADD A CONTACT EMAIL ADDRESS HERE
classifiers =
    Environment :: Web Environment
    Framework :: Django
    Framework :: Django :: 2.2
    Framework :: Django :: 3
    Intended Audience :: Developers
    License :: OSI Approved :: GNU General Public License v3 (GPLv3) # CHANGE THE LICENSE IF YOU WANT
    Programming Language :: Python
    Programming Language :: Python :: 3
    Topic :: Internet :: WWW/HTTP
    Topic :: Internet :: WWW/HTTP :: Dynamic Content

[options]
include_package_data = true
packages = find:
install_requires =
    # ADD YOUR DEPENDENCIES HERE
    # ONE PER LINE