Add Informal Foot Path preset (#493)

* Add Informal Foot Path preset

* Add informal to `moreFields` in Foot Path preset

* Make preset unsearchable

data/presets/highway/footway.json

@@ -11,6 +11,7 @@
     "moreFields": [
         "covered_no",
         "dog",
+        "informal",
         "lit",
         "maxweight_bridge",
         "not/name",

data/presets/highway/footway/_informal.json

@@ -0,0 +1,34 @@
+{
+    "icon": "fas-shoe-prints",
+    "fields": [
+        "surface",
+        "width",
+        "access",
+        "trail_visibility",
+        "smoothness",
+        "incline"
+    ],
+    "moreFields": [
+        "covered_no",
+        "dog",
+        "informal",
+        "lit",
+        "maxweight_bridge",
+        "sac_scale",
+        "stroller",
+        "structure",
+        "wheelchair"
+    ],
+    "geometry": [
+        "line"
+    ],
+    "tags": {
+        "highway": "footway",
+        "informal": "yes"
+    },
+    "reference": {
+        "key": "informal"
+    },
+    "name": "Informal Foot Path",
+    "searchable": false
+}