expose more config in use Surface.Catalogue

[olivermt]

surface-ui/surface_site#27 we should really expose the possible prop settings for #Code in the playground macro usage, so you can expose more lines.. some of my playground and examples (like table) should also show the stuff above render(..) to be even better docs

[msaraiva]

@olivermt would it be enough to have a link to the source of the example?

Additionally, you can still add any code snippet to the @moduledoc of the example. Like:

I could even add support for code highlighting for the snippets ;)