Add vintage_url to schema.json

Author: Dimitar5555

schema.json

@@ -105,6 +105,10 @@
                         "boolean"
                     ]
                 },
+                "vintage_url": {
+                    "description": "A URL for a GeoJSON file containing vintage information for the imagery",
+                    "type": "string"
+                },
                 "id": {
                     "description": "A unique identifier for the source; used in imagery_used changeset tag",
                     "pattern": "^[-_.A-Za-z0-9]+$",