Add support for Roboconf DSL in highlight.js

[vincent-zurczak]

https://highlightjs.org/

This will be useful for reveal.js based presentations that show Roboconf code.

[vincent-zurczak]

Done and submitted here.

[vincent-zurczak]

There is an issue with comments when there are components.
See this page. This one does not work well too...

There is also a problem with instances... See here.