Add Shortcut with multible Markers

[simonfrey]

1. Copy the "layouts/shortcodes/leaflet-simple.html" to a new Shortcut ""layouts/shortcodes/leaflet-multible-markers.html".
2. Change the simple shortcut in a way to accept multible markers (maybe via JSON structure?)

The hugo shortcut for the multible marker function should look somehow like this: {{< leaflet-multible-markers mapHeight='[MAPHEIGHT]' mapWidth='[MAPWIDTH]' mapLon='[MAPLON]' mapLat='[MAPLAT]' markers='{["markerLon"="[MARKERLON]" "markerLat"="[MARKERLAT]" "markerContent"="[MARKERCONTENT]"]}'>}}

[guyou]

I'm interest in such feature as I plan to create a map of my hiking-related posts.

[gyldensaa]

I would also love love such a feature with an array of markers. Multiple marker on map to keep track of owls nests.