feat: 게임 인트로 화면 추가

Gameton-06/Assets/Gameton/Scripts/Scenes/IntroScene.cs

@@ -0,0 +1,33 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+namespace TON
+{
+    public class IntroScene : SceneBase
+    {
+        public override IEnumerator OnStart()
+        {
+            // Intro 씬을 비동기로 로드한다.
+            AsyncOperation asyncLoad = SceneManager.LoadSceneAsync("Intro", LoadSceneMode.Single);
+
+            // 로드가 완료될 때 까지 yield return null 을 하면서 기다린다
+            while (!asyncLoad.isDone)
+            {
+                yield return null;
+            }
+
+            UIManager.Show<IntroUI>(UIList.IntroUI);
+
+        }
+
+
+        public override IEnumerator OnEnd()
+        {
+            yield return null;
+
+            UIManager.Hide<IntroUI>(UIList.IntroUI);
+        }
+    }
+}