Include method/function source in documentation

[jasonl99]

I think it would be useful to include the source of each method (minus the documentation that has already been extracted) in an initially-collapsed element. I've tried to look at the code and figure out how to do this, but it's way over my head :).

There'd be a "Show Source" button that would toggle visibility, and show something like this:

version: ->
    JSON.parse(
      FS.readFileSync(Path.join(__dirname, '..', 'package.json'), 'utf-8')
    )['version']

[waissbluth]

I support this; it would be extremely useful. This was proposed three years ago here #16