Add documentation link to readme

Author: tylertreat

README.md

@@ -5,6 +5,8 @@ Simple Python client for interacting with Google BigQuery.
 
 This client provides an API for retrieving and inserting BigQuery data by wrapping Google's low-level API client library. It also provides facilities that make it convenient to access data that is tied to an App Engine appspot, such as request logs.
 
+[Documentation](http://tylertreat.github.io/BigQuery-Python/)
+
 # Installation
 
 `pip install bigquery-python`