Add lane_markings field (#479)

data/fields/lane_markings.json

@@ -0,0 +1,10 @@
+{
+    "key": "lane_markings",
+    "type": "check",
+    "label": "Lane Markings",
+    "terms": [
+        "centerline",
+        "striped",
+        "unstriped"
+    ]
+}

data/presets/highway/primary.json

@@ -18,6 +18,7 @@
         "flood_prone",
         "incline",
         "junction_line",
+        "lane_markings",
         "lit",
         "maxheight",
         "maxspeed/advisory",

data/presets/highway/residential.json

@@ -15,6 +15,7 @@
         "flood_prone",
         "incline",
         "junction_line",
+        "lane_markings",
         "lit",
         "maxheight",
         "maxspeed/advisory",