Create static_caravans.json

Key is used with tourism related features. Also see #26

Author: kjonosm

data/fields/static_caravans.json

@@ -0,0 +1,11 @@
+{
+    "key": "static_caravans",
+    "type": "check",
+    "label": "Mobile Homes",
+    "terms": [
+        "House Trailers",
+        "Park Home",
+        "Static Caravans",
+        "Trailer home"
+    ]
+}