add long description to pypi page

Author: jbonzo

setup.py

@@ -10,12 +10,20 @@
     print("no version supplied")
     sys.exit(1)
 
+def get_readme_md_contents():
+    """read the contents of your README file"""
+    with open("README.md", encoding='utf-8') as f:
+        long_description = f.read()
+        return long_description
+
 setup(
     name="polygon-api-client",
     version=version,
     description="Polygon API client",
-    author_email="[email protected]",
-    url="https://github.com/Polygon-io/client-python",
+    long_description=get_readme_md_contents(),
+    long_description_content_type="text/markdown",
+    author_email="[email protected]",
+    url="https://github.com/polygon-io/client-python",
     packages=find_packages(),
     classifiers=[
         "License :: OSI Approved :: MIT License",