I've started creating a syntax highlighting plugin for Atom for use in Hugo.
You can download/install it at https://atom.io/packages/language-hugo
The repo is https://github.com/mattstratton/language-hugo
This is very much a WIP; I've only spent a little over an hour on it (I know this thanks to wakatime, and I plan to implement some more stuff, but I really would appreciate some testing!
Right now, it runs on HTML files and MD files; I'd really like to figure out a way to have it only implement the grammar if it can tell that it's in a Hugo project (I haven't much messed with that functionality yet) but it doesn't seem to mess with my other projects too much
Feedback (and PR's!) totally welcome!