slightly better syntax highlighting

[tamagokun]

What's there now is pretty good. But I think I can do better:

http://atelierbram.github.io/Base2Tone-prism/demo/pool/dark/

https://carbon.now.sh/?bg=rgba(30,30,30,1)&t=duotone-dark&l=javascript&ds=true&wc=true&wa=true&pv=48px&ph=32px&ln=false