Allow for non-static example data

[Log1x]

Thanks for the PR. Not against this whatsoever, but could you provide a use-case/example for needing this?

[broskees]

@Log1x Sure. The use case I ran into was I wanted a default image url from my theme and wanted to use the public_path() function to resolve it. I could not do this though because the example variable is static.

Basically any time you want to use a method/function call in the example data, you would need to use the example() method.

[broskees]

@Log1x Anything else I can do to get this merged? Found myself needing it again today.

[dashw00d]

You could always do:

...
use Roots\Acorn\Application;
...

public function __construct(Application $app)
{
    $this->example = $this->example();

    parent::__construct($app);
}