[SOURCES] Add Boxcar commuter bus GTFS feed (NJ-NYC)

Boxcar operates private commuter bus routes between New Jersey
and New York City (13 routes, 91 trips). Feed is auto-generated
daily from live schedule data.

Feed URL: https://boxcar-gtfs.vercel.app/api/gtfs
Website: https://www.boxcar.com

Author: itsjoeco

catalogs/sources/gtfs/schedule/us-new-jersey-boxcar-gtfs-3082.json

@@ -0,0 +1,20 @@
+{
+    "mdb_source_id": 3082,
+    "data_type": "gtfs",
+    "provider": "Boxcar",
+    "name": "Boxcar Commuter Bus",
+    "location": {
+        "country_code": "US",
+        "subdivision_name": "New Jersey",
+        "bounding_box": {
+            "minimum_latitude": 40.5700,
+            "maximum_latitude": 41.0200,
+            "minimum_longitude": -74.6500,
+            "maximum_longitude": -73.9600
+        }
+    },
+    "urls": {
+        "direct_download": "https://boxcar-gtfs.vercel.app/api/gtfs"
+    },
+    "feed_contact_url": "https://www.boxcar.com"
+}