Fix docs in landuse, place and poi

layers/landuse/landuse.yaml

@@ -1,7 +1,7 @@
 layer:
   id: "landuse"
   description: |
-      Landuse is used to describe use of land by humans.At lower zoom levels this is
+      Landuse is used to describe use of land by humans. At lower zoom levels this is
       from Natural Earth data for residential (urban) areas and at higher zoom levels mostly OSM `landuse` tags.
   buffer_size: 4
   fields:

layers/place/place.yaml

@@ -14,7 +14,7 @@ layer:
           [`admin_level`](http://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative#admin_level)
           of the boundary the place is a capital of.
       values: [2, 4]
-    class: |
+    class:
       description: |
           Original value of the
           [`place`](http://wiki.openstreetmap.org/wiki/Key:place) tag.

layers/poi/poi.yaml

@@ -13,7 +13,8 @@ layer:
         this field will contain the same value as `subclass`.
         But for example for schools you only need to style the class `school` to filter the subclasses `school`
         and `kindergarten`. Or use the class `shop` to style all shops.
-    subclass: |
+    subclass:
+      description: |
           Original value of either the
           [`amenity`](http://wiki.openstreetmap.org/wiki/Key:amenity),
           [`leisure`](http://wiki.openstreetmap.org/wiki/Key:leisure),
@@ -24,9 +25,9 @@ layer:
           tag.  Use this to do more precise styling.
     rank: |
         The POIs are ranked ascending according to their importance within a grid. The `rank` value shows the
-        local relative importance of a POI within it's cell in the grid. This can be used to reduce label density at z14.
-        Since all POIs already need to be contained at `z14` you can use `less than rank=10` epxression to limit
-        POIs. At some point like z17 you can show all POIs.
+        local relative importance of a POI within it's cell in the grid. This can be used to reduce label density at *z14*.
+        Since all POIs already need to be contained at *z14* you can use `less than rank=10` epxression to limit
+        POIs. At some point like *z17* you can show all POIs.
   datasource:
     geometry_field: geometry
     srid: 900913