Implement feature IDs in aerodrome_label and mountain_peak (#1176)

layers/aerodrome_label/aerodrome_label.yaml

@@ -1,5 +1,5 @@
 layer:
-  id: "aerodrome_label"
+  id: aerodrome_label
   description: |
       [Aerodrome labels](http://wiki.openstreetmap.org/wiki/Tag:aeroway%3Daerodrome)
   buffer_size: 64

layers/mountain_peak/mountain_peak.yaml

@@ -15,7 +15,7 @@ layer:
       - peak
       - volcano
     ele: Elevation (`ele`) in meters.
-    ele_ft: Elevation (`ele`) in feets.
+    ele_ft: Elevation (`ele`) in feet.
     rank: Rank of the peak within one tile (starting at 1 that is the most important peak).
   datasource:
     geometry_field: geometry