[Gimp-web] Microdata markup formats

I'm in the middle of adding micordata markup the WGO and was wondering if
anyone had any input concerning implementation, types, or formats.

At the moment I'm going to focus on both schema.org microdata (considering
JSON-LD, but likely microdata atm) and opengraph.  I can't seem to find any
issues with using both at the same time.  If someone knows, please chime in.