Include GeoJSON with demographic data returns?

[Joshdpaul]

The EPA-Justice project PI's found a lot of value in showing the spatial boundaries in the NCR demographic data viz (i.e., showing the polygon and spatial area that was surveyed to gather the demographic data that's being displayed) as this cuts down on confusion between place name and actual spatial extent. (For example, what spatial area are you talking about when you say "Fairbanks"?)

As of now, the demographics endpoint in our data API does not return the polygon, just the demographic data. It'd be nice to find a way to include the polygon as well, perhaps as GeoJSON? Maybe omit from any CSV formatted output?