update readme

README.md

@@ -1,6 +1,7 @@
 article-downloader
 ==================
-[![Build Status](https://travis-ci.org/eddotman/article-downloader.svg?branch=master)](https://travis-ci.org/eddotman/article-downloader)
+[![Build Status](https://travis-ci.org/eddotman/article-downloader.svg?branch=master)](https://travis-ci.org/eddotman/article-downloader) [![Documentation Status](https://readthedocs.org/projects/article-downloader/badge/?version=latest)](https://readthedocs.org/projects/article-downloader/?badge=latest)
+
 
 Uses publisher APIs to programmatically retrieve large amounts of scientific journal articles for text mining.
 Primarily built for Elsevier's text mining API; support for other APIs is gradually being added.
@@ -15,6 +16,9 @@ It's usually best to add your API key to your environment variables with somethi
 
 You can find DOIs using a CSV where the first column corresponds to search queries, and these queries will be used to find articles and retrieve their DOIs.
 
+##Documentation
+You can read the documentation for this repository [here](http://article-downloader.readthedocs.org/en/latest/).
+
 ##Examples
 
 ###Downloading a single article