Add doc status to readme

Author: nahum365

README.md

@@ -1,6 +1,7 @@
 # python-nestdeviceaccess
 
-[![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0) [![Build Status](https://travis-ci.com/nahum365/python-nestdeviceaccess.svg?branch=master)](https://travis-ci.com/nahum365/python-nestdeviceaccess) [![codecov](https://codecov.io/gh/nahum365/python-nestdeviceaccess/branch/master/graph/badge.svg?token=ZC5F0CLBNJ)](undefined)
+[![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0) [![Build Status](https://travis-ci.com/nahum365/python-nestdeviceaccess.svg?branch=master)](https://travis-ci.com/nahum365/python-nestdeviceaccess) [![Documentation Status](https://readthedocs.org/projects/python-nestdeviceaccess/badge/?version=latest)](https://python-nestdeviceaccess.readthedocs.io/en/latest/?badge=latest)
+ [![codecov](https://codecov.io/gh/nahum365/python-nestdeviceaccess/branch/master/graph/badge.svg?token=ZC5F0CLBNJ)](undefined)
 
 
 A Python wrapper around the Nest Device Access API. For use in integrating Nest Devices into other smart home systems.