Currently there is no syntax highlighting for the ZenScript examples in the CraftTweaker documentation.
https://github.com/codetaylor/artisan-worktables/blob/master/ZENSCRIPT.md
https://github.com/codetaylor/artisan-worktables/blob/master/ZENSCRIPT_ADVANCED.md

There obviously isn't syntax support for ZenScript in GitHub, but you can use a similar language to provide the syntax highlighting. I suggest JavaScript. Here's an example of what ZenScript looks like with JavaScript syntax highlighting: https://github.com/Yuudaari/soulus/blob/master/docs/CRAFTTWEAKER.md

This will be fixed when b12fc4a merges into the master branch.