Update spatial_shader.rst

Changes WORLD_NORMAL_MATRIX to MODEL_NORMAL_MATRIX

Author: CURR-E

tutorials/shaders/shader_reference/spatial_shader.rst

@@ -217,7 +217,7 @@ shader, this value can be used as desired.
 +----------------------------------------+--------------------------------------------------------+
 | inout mat4 **MODEL_MATRIX**            | Model space to world space transform.                  |
 +----------------------------------------+--------------------------------------------------------+
-| inout mat3 **WORLD_NORMAL_MATRIX**     |                                                        |
+| inout mat3 **MODEL_NORMAL_MATRIX**     |                                                        |
 +----------------------------------------+--------------------------------------------------------+
 | inout mat4 **PROJECTION_MATRIX**       | View space to clip space transform.                    |
 +----------------------------------------+--------------------------------------------------------+