Add beach class to poi.yaml

Could also be set in "attraction" (but I see it as too general for beach) or "swimming" (but beaches are used for more things than swimming, as opposed to swimming pools)

layers/poi/poi.yaml

@@ -82,6 +82,8 @@ layer:
           subclass: ['bar', 'nightclub']
         harbor:
           subclass: ['marina', 'dock']
+        beach: 
+          subclass: ['beach']
         car:
           subclass: ['car', 'car_repair', 'car_parts', 'taxi']
         hospital: