Add aeroway

Home.md

@@ -9,6 +9,7 @@ The **OpenMapTiles** wiki contains the generated layer documentation which can a
 - [housenumber](housenumber)
 - [landcover](landcover)
 - [landuse](landuse)
+- [aeroway](aeroway)
 - [park](park)
 - [place](place)
 - [poi](poi)

Makefile

@@ -34,6 +34,9 @@ building.md: openmaptiles
 place.md: openmaptiles
 	generate-doc openmaptiles/layers/place/place.yaml --diagram place > place.md && generate-etlgraph openmaptiles/layers/place/place.yaml && dot -Tpng openmaptiles/layers/place/etl_place.dot -o etl_place.png
 
+aeroway.md: openmaptiles
+	generate-doc openmaptiles/layers/aeroway/aeroway.yaml --diagram aeroway > aeroway.md && generate-etlgraph openmaptiles/layers/aeroway/aeroway.yaml && dot -Tpng openmaptiles/layers/aeroway/etl_aeroway.dot -o etl_aeroway.png
+
 landuse.md: openmaptiles
 	generate-doc openmaptiles/layers/landuse/landuse.yaml --diagram landuse > landuse.md && generate-etlgraph openmaptiles/layers/landuse/landuse.yaml && dot -Tpng openmaptiles/layers/landuse/etl_landuse.dot -o etl_landuse.png
 

aeroway.md

@@ -0,0 +1,27 @@
+# aeroway
+
+Aeroway polygons based of OpenStreetMap [aeroways](http://wiki.openstreetmap.org/wiki/Aeroways).
+Airport buildings are contained in the **building** layer but all
+other airport related polygons can be found in the **aeroway** layer.
+
+## Fields
+
+### class
+
+The original value of the [`aeroway`](http://wiki.openstreetmap.org/wiki/Key:aeroway) tag.
+
+Possible values:
+
+- `aerodrome`
+- `heliport`
+- `runway`
+- `helipad`
+- `taxiway`
+- `apron`
+
+
+## Mapping
+
+![](aeroway.png)
+
+

boundary.md

@@ -12,8 +12,19 @@ but for most styles it makes sense to just style `admin_level=2` and `admin_leve
 
 OSM [admin_level](http://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative#admin_level)
 indicating the level of importance of this boundary.
+The `admin_level` corresponds to the lowest `admin_level`
+the line participates in.
 At low zoom levels the Natural Earth boundaries are mapped to the equivalent admin levels.
 
+### disputed
+
+Mark with `1` if the boundary is disputed.
+
+Possible values:
+
+- `0`
+- `1`
+
 
 ## Mapping