Add Flooring Factories Outlets to Showcase (#3666)

Added a website made for a client... built with gatsby / netlify :)

Author: akadop

README.md

@@ -142,6 +142,7 @@ Websites built with Gatsby:
   ([source](https://github.com/yerevancoder/yerevancoder.github.io))
 * [unrealcpp](https://unrealcpp.com/) ([source](https://github.com/Harrison1/unrealcpp-com))
 * [several levels](https://severallevels.io/) ([source](https://github.com/Harrison1/several-levels))
+* [Flooring Factories Outlets](https://www.flooringfactoriesoutlets.com/)
 
 ## Docs