Consider better default image sizes

[bacoords]

Fränk Klein has a great article about using the content and wide max-widths as the default sizes for medium and large images:

https://wpdevelopment.courses/articles/performant-images-in-block-themes/

Could probably use a function to generate them automatically from theme.json

https://www.briancoords.com/generate-css-variables-for-any-global-style-assigned-in-the-site-editor/