Example
<div id="map" style="height:300px"></div>
Javascript
<script src="../../vendors/leaflet/leaflet.js"></script>
<script src="../../vendors/leaflet.markercluster/leaflet.markercluster.js"></script>
<script src="../../vendors/leaflet.tilelayer.colorfilter/leaflet-tilelayer-colorfilter.min.js"></script>
stylesheet
<link href="../../vendors/leaflet/leaflet.css" rel="stylesheet" />
<link href="../../vendors/leaflet.markercluster/MarkerCluster.css" rel="stylesheet" />
<link href="../../vendors/leaflet.markercluster/MarkerCluster.Default.css" rel="stylesheet" />