Add member label-node to metadata

Thanks for creating OSM-Boundaries! It helps a lot!

There's one thing which I still need to do as a separate step after downloading data from here: Getting the recommended label position directly from OSM. It would be great if this could be integrated in the metadata somehow to save that extra step.

Maybe it could be added to the Tags or as a separate property, like

"properties": { "osm_id": -365331, "label_position": { "lat":42.6384261,"lon":12.6742970 }, ...}

Here's what I'm doing currently (example Italy)

Manual approach:

1. get ID from the country I'm interested in from the OSM-B data, e.g. Italy 365331
2. Visit Page https://www.openstreetmap.org/relation/365331
3. Observe orange circle north of Rome which is the label position
4. Scroll to bottom, expand Members Section
5. Scroll again (or search for "label"), find  "Node Italy (26347360) as label"
6. Click link and get position from page

Scripted:

1. Download https://www.openstreetmap.org/api/0.6/relation/#{osm_id.abs}.json, e.g. https://www.openstreetmap.org/api/0.6/relation/365331.json
2. find elements[0].members where role=="label"
3. download https://www.openstreetmap.org/api/0.6/#{type}/#{ref}.json, e.g. https://www.openstreetmap.org/api/0.6/node/26347360.json
4. find lat, lon