create front end routes!

[QueMona98]

The purpose of this issue is to create routes to each of the front end pages (i.e. sign up, login, etc.). They will be held in the App.js file! The following line should be in the App.js file:

import { BrowserRouter, Route, Switch } from 'react-router-dom';

This will import the components necessary for creating routes to each of our pages!