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

data/maps/FourIsland/map.json

@@ -280,5 +280,14 @@
       "player_facing_dir": "BG_EVENT_PLAYER_FACING_ANY",
       "script": "FourIsland_EventScript_LoreleisHouseSign"
     }
+  ],
+  "heal_locations": [
+    {
+      "id": "HEAL_LOCATION_FOUR_ISLAND",
+      "x": 18,
+      "y": 21,
+      "respawn_map": "MAP_FOUR_ISLAND_POKEMON_CENTER_1F",
+      "respawn_npc": 1
+    }
   ]
 }