Use three-layer library

[kamil-adam]

This package is aimed at being a modern, production-level, batteries-included starting template for writing web servers with Haskell on backend and Elm on frontend. It follows the Three Layer Cake. architecture pattern.

https://github.com/holmusk/three-layer
https://www.parsonsmatt.org/2018/03/22/three_layer_haskell_cake.html