add scene transition

Assets/Scripts/GameSceneManager.cs

@@ -0,0 +1,32 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+// Manages scene-specific info, WILL be destroyed on load, and there is one of these
+// in each scene
+public class GameSceneManager : MonoBehaviour
+{
+    public static GameSceneManager Instance { get; private set; }
+
+    // This is a list of doors that take us to different scenes. We'll use this
+    // to tell the GameManager which door to put us at when we enter a new scene.
+    public List<SceneDoor> SceneDoors;
+
+    public SceneDoor GetDoorWithId(int id)
+    {
+        return SceneDoors.Find(x => x.DoorId == id);
+    }
+
+    private void Awake()
+    {
+        // If there is an instance, and it's not me, delete myself.
+
+        if (Instance != null && Instance != this)
+        {
+            Destroy(this);
+        }
+        else
+        {
+            Instance = this;
+        }
+    }
+}