Added type definitions and use correct import syntax for images

Author: Niels de Bruin

Diff for: packages/react-scripts/template/images.d.ts

@@ -0,0 +1,3 @@
+declare module '*.svg'
+declare module '*.png'
+declare module '*.jpg'

Diff for: packages/react-scripts/template/src/App.tsx

@@ -1,7 +1,7 @@
 import * as React from 'react';
 import './App.css';
 
-const logo = require('./logo.svg');
+import logo from './logo.svg';
 
 class App extends React.Component {
   render() {