RFE: Update blog posts

[TPS]

@joppuyo I came here after running into & really liking your posts
Is WebP really better than JPEG? & What’s the best lossless image format? Comparing PNG, WebP, AVIF, and JPEG XL, & became impressed that you're developing on JXL. I'd really want to encourage you to update both (but especially the 1st) posts w/ your further JXL results.

[joppuyo]

Hey @TPS

Thanks for your interest!

The blog post about lossless image formats should be up-to-date, there probably haven't been too many changes between cjxl v0.3.7 and v0.6.1.

The article about lossy compression is a few years old and I'm working on a new version of the comparison, using Buutteraugli instead on DSSIM and JPEG XL included in the comparison.

[TPS]

I look forward to it!

As a note, the author of colorist doesn't recommend using it for this kind of image → AVIF conversion, but to use libavif instead.