Added basic features

Assets/Scripts/Manager/StartMenuManager.cs

@@ -0,0 +1,34 @@
+using UnityEngine;
+
+public class StartMenuManager : MonoBehaviour
+{
+    [SerializeField]
+    private GameObject _menuPanelUI;
+    [SerializeField]
+    private GameObject _settingPanelUI;
+
+    private void Awake()
+    {
+        _menuPanelUI.SetActive(true);
+        _settingPanelUI.SetActive(false);
+    }
+
+    public void StartGame()
+    {
+    }
+
+    public void SetSettingPanelActive(bool value)
+    {
+        _settingPanelUI.SetActive(value);
+        _menuPanelUI.SetActive(!value);
+    }
+
+    public void Quit()
+    {
+#if UNITY_EDITOR
+        UnityEditor.EditorApplication.ExitPlaymode();
+#else
+        Application.Quit();
+#endif
+    }
+}