accessibility compliance for syntax highlighting

[thescientist13]

Summary

Coming out of the Lighthouse report for #30 / #57 , noticed that the syntax highlighting theme is getting flagged by Lighthouse.

Details

Would be good to resolve this and check it across all pages of the site (before launch if possible) from our end, (maybe as part of #82 ?)

[DevLab2425]

Not sure what the priority is here, but would be happy to take this on when it's ready.

[thescientist13]

Sure!

We do some tweaks to the Prisma theme in our theme.css, so probably a good place to start poking around in