Revert "Remove callbacks from samples"

This reverts commit e715a7e67f.

samples/NodeJSElectron/src/index.ts

@@ -1,5 +1,5 @@
 import { app, BrowserWindow } from 'electron';
-import { VelopackApp } from "velopack";
+import { VelopackApp, setVelopackLogger } from "velopack";
 import { initializeUpdates } from "./update"
 // This allows TypeScript to pick up the magic constants that's auto-generated by Forge's Webpack
 // plugin that tells the Electron app where to look for the Webpack-bundled app code (depending on
@@ -9,6 +9,7 @@ declare const MAIN_WINDOW_PRELOAD_WEBPACK_ENTRY: string;
 
 // VelopackApp should be the first thing to run in startup
 // as it may need to quit / restart the application at certain points
+setVelopackLogger((lvl, msg) => console.log(`Velopack [${lvl}] ${msg}`));
 VelopackApp.build().run();
 
 // Configure IPC listener for Velopack update messages