Support for font weight, style and duotone

[screaming-snake-case]

It would be great if the package could get support for multiple style options of the same icon.
Just like they do with font awesome.

A proper way to handle this would be using query params in the filenames and directories.

My suggestions would be:
my-icon-dir?weight=300/*
Would result in every icon in the my-icon-dir to use the font weight of 300. (if param not profited use the default 400).
my-first-icon.svg?weight=300
Would result in the icon my-first-icon to use a font weight of 300. (if param not profited use the default 400).

my-icon-dir?style=italic/*
Would result in every icon in the my-icon-dir to use the font style of italic. (if param not provided use the default normal).
my-first-icon.svg?style=italic
Would result in the icon my-first-icon to use the font style of italic. (if param not provided use the default normal).

my-icon-dir?duotone=after/*
Would result in every icon in the my-icon-dir to use the after pseudo element. (if param not provided use the default before).
my-first-icon.svg?duotone=after
Would result in the icon my-first-icon to use the after pseudo element. (if param not provided use the default before).

the after pseudo element should be positioned absolute and have a opacity of .5 so the end user of the icons has a functional default styling for duotone icons.

of course the documentation that is generated should be updated to support this as well.