add long_description_content_type

Author: Chilipp

setup.py

@@ -15,6 +15,7 @@ def readme():
       description=(
           'Create an argparse.ArgumentParser from function docstrings'),
       long_description=readme(),
+      long_description_content_type="text/x-rst",
       classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Intended Audience :: Developers',