add React reference

Author: rwieruch

README.md

@@ -2,7 +2,7 @@
 
 Use Case: Learning best color matches of font and background color for an improved web accessibility.
 
-This example project demonstrates how neural networks may be used to solve a binary classification problem. It uses [deeplearn.js](https://deeplearnjs.org/) to predict accessible font colors based on background colors. [Read more about it](https://www.robinwieruch.de/neural-networks-deeplearnjs-javascript) or find the discussion on [Hacker News](https://news.ycombinator.com/item?id=15855399).
+This example project demonstrates how neural networks may be used to solve a binary classification problem. It uses [deeplearn.js](https://deeplearnjs.org/) to predict accessible font colors based on background colors. [Read more about it](https://www.robinwieruch.de/neural-networks-deeplearnjs-javascript). If you have problems to follow the view layer implementation with React, checkout [this book](https://roadtoreact.com/) to learn the fundamentals of it.
 
 ![nov-26-2017 16-15-23](https://user-images.githubusercontent.com/2479967/33238261-0c4306f6-d2c5-11e7-9ce8-4e661a307b85.gif)