Add README as long description

Author: mworchel

setup.py

@@ -2,6 +2,7 @@
 
 # -*- coding: utf-8 -*-
 import os
+from pathlib import Path
 import sys
 import subprocess
 
@@ -100,6 +101,7 @@ def build_extension(self, ext):
             ["cmake", "--build", "."] + build_args, cwd=self.build_temp
         )
 
+long_description = (Path(__file__).parent / "README.md").read_text()
 
 # The information here can also be placed in setup.cfg - better separation of
 # logic and declaration, and simpler if you include description/version in a file.
@@ -111,6 +113,8 @@ def build_extension(self, ext):
     author_email="m.worchel@campus.tu-berlin.de",
     license='MIT',
     url='https://github.com/mworchel/xatlas-python',
+    long_description=long_description,
+    long_description_content_type='text/markdown',
     ext_modules=[CMakeExtension("xatlas")],
     cmdclass={"build_ext": CMakeBuild},
     zip_safe=False,