[FR] Support converting to AVIF images

[ShivamJoker]

Is your feature request related to a problem? Please describe. A lot of devices and browsers have started to support AVIF which is the best format in the market right now but just relying on WebP won't be the greatest deal.

Describe the solution you'd like I would like image-script to support AVIF so that it can be use a replacement of libraries like sharp.