Better text hightlighthing in editor

Current text hightlighthing needs some improvements, text is very monochrone overall.

1. <code> blocks are really hard to distinguish from regular text, you should consider adding some background at least to make it more readable (look at how it looks in github dark/light mode, much more readable)
2. consider adding accent colors for links, either the default blue or the accent color from collection (or make that adjustable )

I think these two changes would greatly improve readability