Fix docs in landuse, place and poi

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