aspect-ratio uses height/width instead of the correct width/height

[asgerb]

According to MDN aspect-ratio should be specified as width / height, while blurhash-img is using height / width instead. It would be great to get this aligned with the css implementation of aspect-ratio.

I'll try and make a PR with a fix, although it's my first time working with HTML custom elements, so please bear with me 🙂

[asgerb]

Made #2 to update the implementation