Add translatable strings to bridge field (#1002)

data/fields/bridge_combo.json

@@ -1,5 +1,17 @@
 {
     "key": "bridge",
     "type": "combo",
-    "label": "Type"
+    "label": "Type",
+    "strings": {
+        "options": {
+            "aqueduct": "Aqueduct",
+            "boardwalk": "Boardwalk",
+            "cantilever": "Cantilever Bridge",
+            "covered": "Covered Bridge",
+            "low_water_crossing": "Low Water Crossing",
+            "movable": "Movable Bridge",
+            "trestle": "Trestle Bridge",
+            "viaduct": "Viaduct"
+        }
+    }
 }