Enhancement request: Plots per row instead of per table or query

This came up while developing datasette-enrichments-gmap-elevation.

The enrichment enables the user to specify the latitude and longitude for two points (returned from a table) and returns the elevation profile between those points. The user can also specify the distance along the path between the two points that the elevation profile should cover and the number of points of elevation data the Google Maps API should return. It's currently used to look at the terrain around a ham radio station to determine how much the terrain affects the radio wave launch angle from the antenna. (Slope of the terrain is subtracted from the free-space launch angle of the antenna to give the actual launch angle. A lower launch angle equals a skip off the ionosphere further out and therefore high frequency radio contacts to locations further away.) People might also use the enrichment to visualize the hill they hiked down on their latest outing.

Ultimately, the enrichment returned rows that looked like:

Where each row contains a pair of points and each row contains a chart that profiles the elevation from the starting point on the left towards the endpoint of the path on the right, (restricted to the distance along the path the user requested.

If datasette-plot had a per row option that accepted either an array or json data, it would have saved the implementation here.

Start by reading the linked datasette-enrichments-gmap-elevation implementation and the datasette-plot behavior it works around. Trace how plot data is currently accepted and rendered per table or query, then define the completed behavior as one chart being generated for each row from array or JSON data.