Update Highlightjs

Updated the highlight.js definition for the current version 8.2.0.
The [documentation](http://highlightjs.readthedocs.org/en/latest/api.html#highlightauto-value-languagesubset) does not include a `top` member. When testing, it's actually there.
I've opened an issue on the [highlight.js repository](https://github.com/isagalaev/highlight.js/issues/570) to see if it is just missing in the docs or if there shouldn't be one.