Idea: maps and GeoJSON support

[simonw]

It would be cool if the display_sql could return a column populated with GeoJSON which would the automatically be displayed on a map in the results (or maybe default JS would look for a class="geojson" element output by the display template) - ala https://github.com/simonw/datasette-leaflet-geojson

Then I could render workout routes on a map, or Swarm checkin points.