More flow

[jfirebaugh]

I set out to remove as many anys as I could from popup.js and marker.js, and discovered that I needed a MapMouseEvent type first. So I reorganized map event types and docs, then did the original task.

What's nice about this organization is the documentation for each map event type is next to its entry in the MapEvent enum, so we can see where we're missing documentation (e.g. #4772), or missing enum values.

[mollymerp]

hmm this example actually uses the mouseleave event, not mouseout. Are we not defining the events on L165-167 because they're self explanatory or for some other reason?

[mollymerp]

thanks for doing this! I realize now that we're already missing docs for those three events in my earlier comment and now its just more obvious 😂 . I do think we should maybe remove that see example for mouseout or change the example.

[jfirebaugh]

Yeah, I think I'll just go ahead and add docs for mouseleave etc., and move the example.