Right now, the code blocks (highlight) are not focusable, which makes them hard to navigate or inaccessible to readers using only their keyboards or screenreaders.

This can be fixed by ensuring the elements have a tabindex="0".

See an example of a focusable code block from gov.uk

Originally posted by @trallard in #1095 (comment) -> the effort to add a max-height and scrollbar and making the pre elements focusable are independent.

And since I opened this and have been making plenty of noise, I will send a PR tomorrow.