feature request: allow playground users to view the AST dump when writing a yaml rule

[cameronbrill]

The docs tell us that you can view an AST dump of your code pattern when using the Pattern tab in the playground while the YAML tab shows the captured meta variables. I think this playground is awesome, but would love to be able to see the matched AST nodes produced from yaml rules. It would make iterating on a rule much easier.

[HerringtonDarkholme]

it is pretty hard to design a UI for rule matching.
Any suggestion is welcome.