feat: Add mdn.svg

[bsmth]

Adding an asset we use for existing examples

[pepelsbey]

I think it should be safe to optimize the image (just dropped it to SVGOMG), but it’s also called MDN.svg, and most of the files are lowercase. I wonder if we should keep this one lowercase, too. Would it be too problematic to change all demos to lowercase?

[bsmth]

I wonder if we should keep this one lowercase, too. Would it be too problematic to change all demos to lowercase?

No objections to that, let's lowercase it. It's not deployed here yet, so it's not used anywhere. It shouldn't be a problem, so let's go ahead and rename

[pepelsbey]

Thanks!