Add asset path alias

[Braayy]

I was thinking about the path aliases of other frameworks and because the components, store and etc are global in Mint, the only need for path alias is for the asset and svg directives.

So i did think about using #assets so the whole ../../../../assets/ thing are gone.

An example would be @svg(#assets/icons/plus.svg)

If that is a good idea, i would start coding it.