Syntax highlighter not working

[smilegodly]

What happened:

Was scrolling through dev and noticed no highlighting in the code blocks. Noticed it's also in prod.

What should have happened:
The syntax highlighter we use is https://highlightjs.org/ and the code should be the github highlight theme

How to reproduce it (as precise as possible):
look at the code blocks on dev / prod

Anything else we need to know?:
Here is a picture

And another

Environment:

• OS:
• Browser:

[smilegodly]

I'll work on this.

[manekenpix]

@smilegodly All yours, thank you!

[humphd]

I screwed it up in this PR when I removed import 'highlight.js/styles/github.css';