Move styleguidist custom components to demo folder

Author: onurkerimov

README.md

@@ -20,7 +20,7 @@ A date library agnostic React component for choosing dates and date ranges. Uses
 
 **Live Demo :** [http://adphorus.github.io/react-date-range](http://adphorus.github.io/react-date-range)
 
-![](https://raw.githubusercontent.com/Adphorus/react-date-range/master/demo/assets/ss.png)
+![](https://raw.githubusercontent.com/Adphorus/react-date-range/master/demo/ss.png)
 
 
 ## Getting Started