Cluster locations in event map

[linahanner]

As a Visitor
I want the events to be clustered in the map
So that I have an easier time navigating the map without events cluttering

Idea by Morris to cluster the events in the map when zoomed out.
@karlbeecken suggested doing so with Leaflet.js plugin Markercluster

Uncertain if there are any particular reasons why the event locations have so far been kept unclustered. Is it intentional?