I think that is better to change this to another property, which you can choose what highlighter you want to use. Since in this case you can make some strange things like: 

```yml
pygments: true
rouge: true
```

Maybe change by a `highlighter` property, with defaults to `pygments` and allowing the values `none`, `pygments` and `rouge`. This you ease the treatment on the markdown converter too.

Obviously, you must keep compatibility for  the `pygments` property. For this you can still allowing the old config, but show a deprecation warning to the old configuration.

@mattr- and @parkr, what do you think?