Move heal locations data to their associated map.json (#673)

data/maps/IndigoPlateau_Exterior/map.json

@@ -60,5 +60,14 @@
     }
   ],
   "coord_events": [],
-  "bg_events": []
+  "bg_events": [],
+  "heal_locations": [
+    {
+      "id": "HEAL_LOCATION_INDIGO_PLATEAU",
+      "x": 11,
+      "y": 7,
+      "respawn_map": "MAP_INDIGO_PLATEAU_POKEMON_CENTER_1F",
+      "respawn_npc": 2
+    }
+  ]
 }