Optmize shader structure

Editor/MeterialEditor/UIScopes/ShadingGradeScope.cs

@@ -0,0 +1,23 @@
+using Misaki.ShaderGUI;
+using UnityEditor;
+using UnityEngine;
+
+namespace Misaki.HdrpToon.Editor
+{
+    public class ShadingGradeScope : MaterialUIScope<ShaderGUIExpandable>
+    {
+        protected override ShaderGUIExpandable ExpandableBit => ShaderGUIExpandable.ShadingGrade;
+
+        protected override GUIContent Header => EditorGUIUtility.TrTextContent("Shading Grade Settings");
+
+        public override void LoadMaterialProperties()
+        {
+            throw new System.NotImplementedException();
+        }
+
+        protected override void DrawContent()
+        {
+            throw new System.NotImplementedException();
+        }
+    }
+}