Add README contents as long_description

Author: snoack

MANIFEST.in

@@ -1 +1 @@
-include LICENSE tox.ini test_goto.py
+include README.md LICENSE tox.ini test_goto.py

setup.py

@@ -1,10 +1,16 @@
+import os
 from setuptools import setup
 
+with open(os.path.join(os.path.dirname(__file__), 'README.md')) as file:
+    long_description = file.read()
+
 setup(
     name='goto-statement',
     version='1.1',
     url='https://github.com/snoack/python-goto/',
     description='A function decorator, that rewrites the bytecode, to enable goto in Python',
+    long_description=long_description,
+    long_description_content_type='text/markdown',
     py_modules=['goto'],
     author='Sebastian Noack',
     author_email='sebastian.noack@gmail.com',