FFmpeg now supports JPEG XL and AVIF: how to convert images

I personally was wrong in that I thought AVIF would be the last traditional codec, and future progress would come from ML based compression. But JPEGXL is very impressive. I do think we are close to the end of the road for this approach though, as neural net based compression appears to outperform by many multiplies. I expext everything (major) after JPEGXL to be ML based.