[feature-request] Add zooming capability.

[TheSalarKhan]

This is an awesome project. There's no doubt about it, this is where React should go next.

I am trying it out to build a small hobby project and I want to try out how easy it is to make responsive components. The issue is that the builder UI currently has no option to zoom the view port. Zoom is very important when we're trying to make components responsive from mobile to 4k screens. If I create a Box component with a dimension that's bigger than my screen, there's actually no way to preview it on openchakra without getting a bigger screen.

Thanks <3