Request to add OpenRailwayMap layer to Map

[hemind]

It would be great to have OpenRailwayMap as an overlay map layer on the maps of theCrag. Then user can quickly check the nearby train stations for some crag. This would be very useful for climbers using public transportation which is environment friendly.

Add this layer for leaflet map plugin is easy, just follow this link: https://wiki.openstreetmap.org/wiki/OpenRailwayMap/API#Usage_in_Leaflet

BTW, we could left this layer default off to avoid too much elements on the map.