The readme should reflect that the element that receives virtual.style needs box-sizing: border-box

[mindnektar]

I've spent some time trying to figure out why my react-virtual-list implementation kept scrolling down after I reached the bottom, seemingly increasing the list's size the further I scrolled. After I dug into how this library works, at some point it became really obvious what the problem was: With each list item vanishing above the viewport, more padding was added to the list, which in turn was added to the list's height because I hadn't set box-sizing: border-box on it previously.

If this requirement was included somewhere in the readme, that might prevent some pain getting started. Otherwise, really good job with this!

[mindnektar]

This is a duplicate of #56