preload: Update reason for using dom listeners.

Even though Electron v5 supports numpad keys, we can't add another
accelerator to the same menu item.

app/renderer/js/preload.js

@@ -88,7 +88,8 @@ window.addEventListener('beforeunload', () => {
 
 // electron's globalShortcut can cause unexpected results
 // so adding the reload shortcut in the old-school way
-// Zoom from numpad keys is not supported by electron, so adding it through listeners.
+// electron does not support adding multiple accelerators for a menu item
+// so adding numpad shortcuts here
 document.addEventListener('keydown', event => {
 	if (event.code === 'F5') {
 		ipcRenderer.send('forward-message', 'hard-reload');