Fix: Don't create a second "Help" menu for the "About" dialogs.

mainwindow.cpp

@@ -126,7 +126,8 @@ void MainWindow::on_pushButton_clicked() {
 }
 
 void MainWindow::createHelpMenu() {
-  QMenu* helpMenu   = menuBar()->addMenu(tr("&Help"));
+  QMenu* helpMenu = ui->menu_Help;
+  helpMenu->addSeparator();
   QAction* aboutAct = helpMenu->addAction(tr("&About"), this, &MainWindow::onAboutClicked);
   aboutAct->setStatusTip(tr("Show the application's About box"));