README.md in jekyll-books-0.1.0 vs README.md in jekyll-books-0.1.1

@@ -20,9 +20,13 @@
     $ bundle
 
 Or install it yourself as:
 
     $ gem install jekyll-books
+    
+## Usage
+
+[Usage](https://github.com/erlzhang/jekyll-theme-persephone/blob/master/docs/books.md)
 
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at https://github.com/erlzhang/jekyll-books. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.