Themes: add 'skateboard' as sport pitch option

assets/layers/sport_pitch/sport_pitch.json

@@ -166,6 +166,13 @@
             "es": "Aquí se juega al baloncesto"
           },
           "hideInAnswer": true
+        },
+        {
+          "if": "sport=skateboard",
+          "then": {
+            "en": "This is a skatepark",
+            "nl": "Dit is een skatepark"
+          }
         }
       ],
       "id": "sport_pitch-sport"
@@ -677,4 +684,4 @@
     },
     "open_now"
   ]
-}
+}