Add preset for water=oxbow (#595, #118)

data/presets/natural/water/oxbow.json

@@ -0,0 +1,23 @@
+{
+    "icon": "maki-water",
+    "geometry": [
+        "area"
+    ],
+    "tags": {
+        "natural": "water",
+        "water": "oxbow"
+    },
+    "reference": {
+        "key": "water",
+        "value": "oxbow"
+    },
+    "terms": [
+        "anabranch",
+        "billabong",
+        "cut off",
+        "meander",
+        "oxbow",
+        "resaca"
+    ],
+    "name": "Oxbow Lake"
+}