Hi,
Is there a way to hide workshelf using a command or keyboard shortcut? I mean when I minimize all windows and desktop is showing the workshelf is visible which is normal, but is there a way to hide and show this workshelf using a command or a custom/user defined keyboard shortcut?

You can use Auto-hide (Shelf Properties -> Behavior) to hide the shelf - tick 'Auto-hide after a short delay'.

Modify the 'Auto-Hide Settings' to match your preferences.

I personally prefer to keep the tabs displayed when the shelf is collapsed, but you can hide those as well if you want the Shelf to disappear completely.