Env creation tutorial 2 : grid size inconsistent (#1036)

tutorials/EnvironmentCreation/tutorial2_adding_game_logic.py

@@ -30,8 +30,8 @@ def reset(self, seed=None, options=None):
         self.prisoner_x = 0
         self.prisoner_y = 0
 
-        self.guard_x = 7
-        self.guard_y = 7
+        self.guard_x = 6
+        self.guard_y = 6
 
         self.escape_x = random.randint(2, 5)
         self.escape_y = random.randint(2, 5)
@@ -104,7 +104,7 @@ def step(self, actions):
         return observations, rewards, terminations, truncations, infos
 
     def render(self):
-        grid = np.zeros((7, 7))
+        grid = np.full((7, 7), " ")
         grid[self.prisoner_y, self.prisoner_x] = "P"
         grid[self.guard_y, self.guard_x] = "G"
         grid[self.escape_y, self.escape_x] = "E"