Add progressive administrative levels to layer "boundaries" #138
Description
The "boundaries" layer currently supports only admin levels 2 and 4 (countries and states), displayed at zoom levels 0 and 7 respectively.
The current raster style OpenstreetMap-carto already implements progressive rendering of additional admin levels based on zoom level. Adding the same feature would significantly improve the map's usability for local navigation and context.
Proposed features:
| admin_level | zoom level | description |
|---|---|---|
| 2 | 0 | countries |
| 4 | 7 | state/provinces |
| 6 | 10 | departements/districts |
| 8 | 12 | cities |
| 9 | 12 | city districts |
| 10 | 14 | neighborhoods |
| 11 | 14 | subdivision of neighborhoods |
Complete administrative levels by country
About labeling: in OpenstreetMap-carto, boundaries are labeled along the boundary lines, on the right side of the line. I'm not sure if this feature is achievable with vector tiles and Maplibre, that might be a separate topic. Maybe in a first time, new admin_level feature could be added in "boundary_labels" layer.