Fix broken menu button on non-touchscreen devices

[kbrgl]

The menu button was only working when tapped on touchscreen devices (i.e. it couldn't be clicked with a mouse.) I have fixed this issue and removed Modernizr.

Modernizr is useless for this website because the only thing for which it was being used was to detect touchscreen devices and make the menu button tappable. However, this is pretty redundant because the menu button will work on touchscreen devices anyway.

I have a demo of the fixed website up at http://kbrgl.github.io/devicons