Add shareware support and spawn correctly for difficulty levels

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

lib/features/entities/door_manager.dart

@@ -1,12 +1,13 @@
 import 'dart:math' as math;
 
+import 'package:wolf_dart/classes/sprite.dart';
 import 'package:wolf_dart/features/map/door.dart';
 
 class DoorManager {
   // Key is '$x,$y'
   final Map<String, Door> doors = {};
 
-  void initDoors(List<List<int>> wallGrid) {
+  void initDoors(Sprite wallGrid) {
     doors.clear();
     for (int y = 0; y < wallGrid.length; y++) {
       for (int x = 0; x < wallGrid[y].length; x++) {