[Feature request] Use addresses as well as locations

[AndyClifton]

I have a data file containing locations encoded using a mixture of lat / long pairs and addresses. I would like to be able to add markers for the addresses if possible.

Ideally I could then plot all of the locations in one map using something like...

{% leaflet_map { "zoom" : 5,
                  "center" : [47, 10],
                "providerBasemap": "OpenStreetMap.HOT"} %}
    {%- for item in site.data.map -%}
        {% if item.location.latitude and item.location.longitude %}
            {% leaflet_marker { "latitude" : {{item.location.latitude}},
                        "longitude" : {{item.location.longitude}} } %}
        {% endif %}
    {% if item.location.address %}

    {% endif %}
  {% endfor %}
{% endleaflet_map %}