Rewire create-react-app to use MobX

Install

``bash
$ npm install --save mobx mobx-react react-app-rewire-mobx
`

Add it to your project

* Rewire your app, then modify config-overrides.js

`javascript
const rewireMobX = require('react-app-rewire-mobx');

/ config-overrides.js /
module.exports = function override(config, env) {
config = rewireMobX(config, env);
return config;
}
``

Notes

* Remove experimentalDecorators warning in VSCode