Add setup.cfg (issue #129)

setup.cfg

@@ -0,0 +1,32 @@
+[metadata]
+name = idna
+version = attr: idna.__version__
+author = Kim Davies
+author_email = kim+pypi@gumleaf.org
+description = Internationalized Domain Names in Applications (IDNA)
+license = BSD-3-Clause
+classifiers =
+  Development Status :: 5 - Production/Stable
+  Intended Audience :: Developers
+  Intended Audience :: System Administrators
+  License :: OSI Approved :: BSD License
+  Operating System :: OS Independent
+  Programming Language :: Python
+  Programming Language :: Python :: 3
+  Programming Language :: Python :: 3 :: Only
+  Programming Language :: Python :: 3.5
+  Programming Language :: Python :: 3.6
+  Programming Language :: Python :: 3.7
+  Programming Language :: Python :: 3.8
+  Programming Language :: Python :: 3.9
+  Programming Language :: Python :: 3.10
+  Programming Language :: Python :: 3.11
+  Programming Language :: Python :: 3.12
+  Programming Language :: Python :: Implementation :: CPython
+  Programming Language :: Python :: Implementation :: PyPy
+  Topic :: Internet :: Name Service (DNS)
+  Topic :: Software Development :: Libraries :: Python Modules
+  Topic :: Utilities
+
+[options]
+python_requires = >=3.5