Use the GitHub Repository as url (python#49)

pradyunsg · web-flow · commit ffb755eeee8b · 2020-07-28T22:37:15.000+02:00
This provides more information on the PyPI page for the project, and makes it
easier to reach this repository from the PyPI page.
diff --git a/setup.py b/setup.py
@@ -18,7 +18,7 @@
     long_description=long_description,
     author='PyPA',
     author_email='distutils-sig@python.org',
-    url='https://docs.python.org',
+    url='https://github.com/python/python-docs-theme/',
     packages=['python_docs_theme'],
     include_package_data=True,
     entry_points={
