You are able to create a shortcut for Sign out on Windows 10 computer according to the following instruction.
Video guide on how to create Sign out shortcut in Windows 10:
Step 1: Right-click blank space, point at New on the menu and tap Shortcut in the sub-menu.
Step 2: In the pop-up window, enter c:\windows\system32\shutdown –l, and select Next.
Step 3: Type Sign out or another description to name this shortcut, and then hit Finish.
Instantly, the shortcut of Sign out is created with success, referring to the picture below.