docs: fix represented file fiddle (#40233)

docs/fiddles/features/represented-file/main.js

@@ -7,14 +7,20 @@ function createWindow () {
     height: 600
   })
 
+  win.setRepresentedFilename(os.homedir())
+  win.setDocumentEdited(true)
+
   win.loadFile('index.html')
 }
 
 app.whenReady().then(() => {
-  const win = new BrowserWindow()
+  createWindow()
 
-  win.setRepresentedFilename(os.homedir())
-  win.setDocumentEdited(true)
+  app.on('activate', () => {
+    if (BrowserWindow.getAllWindows().length === 0) {
+      createWindow()
+    }
+  })
 })
 
 app.on('window-all-closed', () => {
@@ -22,9 +28,3 @@ app.on('window-all-closed', () => {
     app.quit()
   }
 })
-
-app.on('activate', () => {
-  if (BrowserWindow.getAllWindows().length === 0) {
-    createWindow()
-  }
-})