Issues with zooming and syntax highlighting

[l8l]

Futhark seems to be an awesome language and the website is a great source for learning about it. I recently finished reading the online book https://futhark-book.readthedocs.io/en/latest/, which was a lot of fun.

I want to make two suggestions regarding the style:

1. Syntax highlighting: Right now, there is no syntax highlighting in the block codes and that is really making it harder to read. Furthermore, a copy button for code blocks would be good, similar to how it is done on many other sites, e.g. in the julia documentation on GPU programming: https://cuda.juliagpu.org/stable/tutorials/introduction/ ,-)

2. When zooming in with STR +, at least in the futhark-book, I have the problem that the menu starts overlapping with the text like in the following screenshot:
   

Ah and maybe an optional dark-mode would be something worth to consider as an alternative to the slightly-yellow background but I guess that is a matter of taste.

I hope this constructive feedback does not bother you! Again, great work and keep it up! = )

[athas]

This is really an issue with https://github.com/diku-dk/futhark-book/. The root cause is that I am not very experienced with web technologies.