Add OS DPI/scale/zoom

[rudiedirkx]

I have my Windows at 1.25 scale/zoom. On OS level, not browser zoom. That means my screen is 1920x1080, but mybrowser.fyi sees 1536x864x. (I didn't calculate, but that should be about 4/5.) Sometimes that's nice to know.

I don't know how to detect it though...

[Andy-set-studio]

That's interesting. I'd love to dive into that a bit further. The width is calculated with window.innerWidth, but there's room for that to be a bit smarter to fix #17.

I'll link this up with that issue as I'll probably fix them all in one run.

Thanks @rudiedirkx!

[rudiedirkx]

I mean the screen, not the window. So probably screen.width, not window.innerWidth. I can't find anything in window or screen larger than screen.width, so maybe it's not detectable.