Infoboxes

We're getting the Infoboxes from parse tree XML, and converting it to a dict with utils.template_to_dict.

• https://en.wikipedia.org/wiki/Help:Infobox
• https://meta.wikimedia.org/wiki/Wiki_syntax

See [page.infobox](https://github.com/siznax/wptools/wiki/Attributes#pageinfobox) in Attributes for an example.