A Neural Network in JavaScript

Excercise inspired by this https://medium.freecodecamp.org/how-to-create-a-neural-network-in-javascript-in-only-30-lines-of-code-343dafc50d49
and this https://synaptic.juancazala.com/#/

https://karpathy.github.io/neuralnets/

Creating and training a neural network using Synaptic.js, / this allows to do deep learning in Node.js and the browser.