Add a nam for center of Nantes

src/crossroads-by-name.json

@@ -79,5 +79,8 @@
     "longitude": 3.0953730289756627},
 "Montpied": {
     "latitude" : 45.76097,
-    "longitude": 3.08957}
+    "longitude": 3.08957},
+"50otages": {
+    "latitude" : 47.22053,
+    "longitude": -1.55454}
 }