MNT: Add long description

Author: effigies

setup.cfg

@@ -5,6 +5,8 @@ subpackage = nipype1
 author = Chris Markiewicz
 author_email = markiewicz@stanford.edu
 description = Tools for importing nipype 1.x interfaces into Pydra
+long_description = file:README.md
+long_description_content_type = text/markdown; variant=CommonMark
 license = Apache License, 2.0
 classifiers =
     Development Status :: 4 - Beta