added assets and updated README.md (#173)

Author: piyushsi

README.md

@@ -326,6 +326,10 @@ The following sites are built with `next-on-netlify`:
 
 [gemini.com](https://gemini.com/)
 
+![bigbinary.com](https://raw.githubusercontent.com/netlify/next-on-netlify/master/assets/showcase-bigbinary.png)
+
+[bigbinary.com](https://bigbinary.com/)
+
 [![next-cms-ghost](https://static.gotsby.org/v1/assets/images/next-cms-ghost-demo.png)](https://netlify.jamify.org)
 
 [Create your own blog and deploy to Netlify!](https://github.com/styxlab/next-cms-ghost)