feat: Implement hillshade layer

Assets/Main.unity

@@ -677,9 +677,11 @@ MonoBehaviour:
   m_Name: 
   m_EditorClassIdentifier: 
   m_layerTile: {fileID: 1412061072}
+  m_layerTileHillshade: {fileID: 1089136493}
   m_layerElement: {fileID: 1602500234}
   m_layerElementSub: {fileID: 303098821}
   m_prefabTile: {fileID: 7683017549812261837, guid: e090edd328c6750478f5849a43a9d278, type: 3}
+  m_prefabTileHillshade: {fileID: 7683017549812261837, guid: d112aa7211e072e489ec497e34c5b57b, type: 3}
   m_prefabBitmapHolder: {fileID: 1455558857588368834, guid: 1a5cf693e0cf6b94390f72f521c151ba, type: 3}
   m_maxMapTileZoom: 10
   m_isEditor: 0
@@ -1068,6 +1070,37 @@ MonoBehaviour:
   m_FlexibleWidth: 1
   m_FlexibleHeight: -1
   m_LayoutPriority: 1
+--- !u!1 &1089136492
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 1089136493}
+  m_Layer: 0
+  m_Name: Map Tiles Hillshade
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 1
+--- !u!4 &1089136493
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 1089136492}
+  serializedVersion: 2
+  m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
+  m_LocalPosition: {x: 0, y: 0, z: -0.5}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 0
+  m_Children: []
+  m_Father: {fileID: 0}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
 --- !u!1 &1345962671
 GameObject:
   m_ObjectHideFlags: 0
@@ -3860,6 +3893,7 @@ SceneRoots:
   m_Roots:
   - {fileID: 376792589}
   - {fileID: 1412061072}
+  - {fileID: 1089136493}
   - {fileID: 1602500233}
   - {fileID: 303098822}
   - {fileID: 1345962672}