Add name_de to documentation

layers/place/place.yaml

@@ -7,7 +7,8 @@ layer:
       We suggest you use different font styles and sizes to create a text hierarchy.
   fields:
     name: The OSM [`name`](http://wiki.openstreetmap.org/wiki/Key:name) value of the POI.
-    name_en: The English `name:en` value or local `name` if not available.
+    name_en: English name `name:en` if available, otherwise `name`.
+    name_de: German name `name:de` if available, otherwise `name` or `name:en`.
     capital:
       description: |
           The **capital** field marks the