Update README.md

update doc url to rtfd

README.md

@@ -13,4 +13,4 @@ The latest documentation is available [here][docs].
 [flask-babel]: http://github.com/mitsuhiko/flask-babel
 [babel]: https://github.com/python-babel/babel
 [pytz]: https://pypi.python.org/pypi/pytz/
-[docs]: https://pythonhosted.org/sanic-babel/
+[docs]: http://sanic-babel.readthedocs.io/