Image optimization pipeline

[robinmetral]

...or maybe as part of brut? (should be optional, it gets Gatsby sites bloated).

Ideally a script that generates optimized images for a few sizes (and maybe webp+avif) and saved them to the filesystem or some CDN.

See:

• https://developer.mozilla.org/en-US/docs/Learn/HTML/Multimedia_and_embedding/Responsive_images
• https://web.dev/serve-responsive-images/
• https://cloudfour.com/thinks/responsive-images-101-definitions/

Use:

• squoosh
• sharp