Serve responsive images

[severo]

Optimize quality/weight ratio for images.

See:

• https://responsivebreakpoints.com/ and https://cloudinary.com/blog/introducing_intelligent_responsive_image_breakpoints_solutions
• Webpack loader: https://github.com/herrstucki/responsive-loader
• Gulp: https://www.npmjs.com/package/gulp-responsive
• Rollup plugins: https://github.com/rollup/rollup-plugin-image, https://github.com/malchata/rollup-plugin-imagemin

The idea could be to create a Rollup plugin, and use it with Svelte.

Features

• define the dimensions in the Svelte component (or use responsivebreakpoints to compute them) (must be read by Rollup)
• use Svelte to fill the srcset attribute
• generate the images at build time (Rollup)

[severo]

Partially solved with https://github.com/severo/occupapp/commit/a5b778674067066fe82bb56dc36ac3d04fa2da26 + https://github.com/severo/pictures

[severo]

Done.