Add relative window size (#2819)

* Add relative window size

* Simplify assign of height and width

packages/apps-electron/src/electron.ts

@@ -2,19 +2,20 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { BrowserWindow, app } from 'electron';
+import { BrowserWindow, app, screen } from 'electron';
 import path from 'path';
 
 const environment = process.env.NODE_ENV || 'production';
 
 function createWindow (): Promise<unknown> {
-  // Create the browser window.
+  const { height, width } = screen.getPrimaryDisplay().workAreaSize;
+
   const win = new BrowserWindow({
-    height: 600,
+    height,
     webPreferences: {
       nodeIntegration: true
     },
-    width: 800
+    width
   });
 
   if (environment === 'development') {