Add basic button for loginpage

src/components/LandingPage/LandingPage.tsx

 import React, { FC } from 'react';
+import Button from '@material-ui/core/Button';
+import { Link } from 'react-router-dom';
 
 export const LandingPage: FC = () => (
   <>
+    <Button variant="contained">
+      <Link to="/auth">Login</Link>
+    </Button>
     <section>
       <h2>What is MoveAid?</h2>