Showing a locality POI should use an "outline" rather than a "pin" UI

[michaelkirk]

From #161 (comment)

Currently, after searching for a POI we render a pin at the POI's position. This works well enough for small things like a shop, but when the POI is a big entity like an entire city, it seems inappropriate and arbitrary to render a pin.

Instead of a pin, we should render an outline or a polygon to highlight the entire area of the locality.

[michaelkirk]

Some related issues from pelias:

include geometry in /places response
pelias/whosonfirst#19 (comment)

create new endpoint for geometries of cities
pelias/api#1121

[maciejla]

I think the same thing should happen with things like landuse=education