Allow CSS images optimization (for example background image)

[pioso]

Hello @Niels-IO,

Thank you for your efforts. Good job!

The package itself works very well, but I've noticed a significant missing feature: optimization of images included in CSS, such as background images (refer to this link for details).

Have you considered this use case before?

Upon a quick review of the code, my initial idea would be to begin with the getImageUrl function (accessible here) and integrate it into an exported API interface. This way, developers could pass the necessary image and current viewport width, and receive an optimized image URL in return.

What are your thoughts on this approach? Does it seem viable to you? Do you have any alternative ideas for extending the package to support images used in CSS?

Best regards