增加A2WToolBox工具集，增加Launch场景核LaunchPanel

Assets/A2WToolBox/Runtime/SceneLoader/ITransition.cs

@@ -0,0 +1,19 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace A2W
+{
+    public interface ITransition
+    {
+        public void Init(Transform parent);
+
+        public void Begin();
+
+        public void Finish();
+
+        public bool IsDone();
+    }
+}
+
+