Rename canvas to game and fix code order and import/export

src/frontend/canvas.js → src/frontend/game.js

-import * from phaser;
+import Phaser from 'phaser';
 
-var scene = {
+function preload ()
+{
+    this.load.image('404', 'http://labs.phaser.io/assets/sprites/phaser3-logo.png')
+}
+function create ()
+{
+    this.add.image(300, 400, '404')
+}
+
+let scene = {
     preload: preload,
     create: create
 };
 
-var config = {
+let config = {
     type: Phaser.AUTO,
     width: 800,
     height: 600,
     scene: scene
 };
 
-var game = new Phaser.Game(config);
+let game = new Phaser.Game(config);
 
-function preload ()
-{
-    this.load.image('404', 'http://labs.phaser.io/assets/sprites/phaser3-logo.png')
-}
-function create ()
-{
-    this.add.image(300, 400, '404')
-}
\ No newline at end of file
+export default game;