update doc

to add religion as subclass on poi layer

layers/poi/poi.yaml

@@ -24,7 +24,8 @@ layer:
           [`station`](http://wiki.openstreetmap.org/wiki/Key:station),
           [`sport`](http://wiki.openstreetmap.org/wiki/Key:sport),
           [`tourism`](http://wiki.openstreetmap.org/wiki/Key:tourism),
-          [`information`](http://wiki.openstreetmap.org/wiki/Key:information)
+          [`information`](http://wiki.openstreetmap.org/wiki/Key:information),
+          [`religion`](http://wiki.openstreetmap.org/wiki/Key:religion)
           or [`shop`](http://wiki.openstreetmap.org/wiki/Key:shop)
           tag.  Use this to do more precise styling.
     rank: |