Update setup.cfg with documentation URL (#539)

* Update setup.cfg

* Update setup.cfg

Co-authored-by: Ray Luo <[email protected]>

---------

Co-authored-by: Ray Luo <[email protected]>

Author: pamelafox

setup.cfg

@@ -4,3 +4,6 @@ universal=1
 [metadata]
 project_urls =
     Changelog = https://github.com/AzureAD/microsoft-authentication-library-for-python/releases
+    Documentation = https://msal-python.readthedocs.io/
+    Questions = https://stackoverflow.com/questions/tagged/msal+python
+    Feature/Bug Tracker = https://github.com/AzureAD/microsoft-authentication-library-for-python/issues