Theme creation: Template ideas

[danieldegroot2]

If not already, allow to create themes from

• (a combination of) presets from some known list (ie. wiki approved tags (and keys)) (or some specific tag).
• objects added/changed by you (or someone else)
• NSI items
• (geotagged images with compatible license from eg. Wikimedia Commons)

And,

• Filter if you want nodes, ways or relations
• Specify an overlay if you want to work from existing (government) data -OT: ofc with a compatible license-
• Confine to some area (eg. based on Nominatim search or OSM id); although this wouldn't be nice for others (so maybe these would be completely private themes..or not).
• Auto-suggest existing icons.

(otherwise) for #173