Introducing a Dark Mode Switcher for the Frontend Default Theme

I suggest adding a Dark Mode Switcher for the default frontend theme.

In the backend that is already implemented nicely.

It is very cool, saves energy and my eyesight. thumbs up

Oh, I just see that someone posted a similar idea already 
https://www.litecart.net/en/forums/5/feature-requests-and-new-ideas/12462/litecart-dark-mode-version

Not clear if the other post is related to the frontend tho.