Now if you double-click the shutdown shortcut on your desktop, Terminal will open, prompting you to enter your user password. Once entered, the timer will begin.

The second and less-imaginatively-named Shortcut Guide allows you to bring up a cheat sheet of available keyboard shortcuts for whatever app is currently active, including the Windows 10 desktop ...

The collaborative DIY web site Instructables has a neat trick for adding a shutdown shortcut to your Windows desktop complete with the shutdown icon (or anywhere else, for that matter).