Make it possible to pass a file reference for data

[thiagodemellobueno]

Would be very nifty if the render function could take a "jsonPath" option.
something like
return template.render.bind(template, getJSONFromFile(options.jsonPath))

[RobLoach]

Ah, like retrieve some extra options from some given .json file? Interesting idea. This could be something we put in where the Twig template is built. Usually it takes it from YAML front-matter, but we could do something like have it be a Twig function that expands the local variable table.

Or something... We'll need to do some thinking.

[thiagodemellobueno]

since kss uses the jsons, we probably want to use the same files. but seems acheivable!