You can add it yourself if you like :)
Navigate to C:\ProgramData\Unified Remote\Remotes\Bundled\Unified\Main\Power (you may need to enable Hidden Folders to see Program Data).
Inside the Power folder, you will see a file "remote.lua". Open with Notepad or any text editor and edit the line:
to:os.execute("shutdown /s /hybrid /f /t " .. sec);
Let me know if you need more help.