Circle size legend

[mikelmaron]

A legend on the map to show what the sizes of circles mean. (We talked about it before, but I forgot to include that in the list of features when we were finalizing things.)

[mikelmaron]

The idea behind this issue was to replicate this kind of legend on the old maps

However the main piece of information this is conveying is the maximum capacity on the map. When looking at where to fit the circle legend into the map, I wondered if a more elegant and straightforward solution would be to simply surface the maximum capacity number. This also has the advantage that the maximum capacity can update dynamically to whatever is currently filtered.

[mikelmaron]

will discuss later if appropriate