Add description for custom vertex values

Piralein · clayjohn · Piralein · commit 88ee7438be88 · 2024-07-13T13:45:02.000+02:00
Co-Authored-By: Clay John &lt;claynjohn@gmail.com&gt;
diff --git a/tutorials/shaders/shader_reference/canvas_item_shader.rst b/tutorials/shaders/shader_reference/canvas_item_shader.rst
@@ -132,9 +132,9 @@ is usually:
 +--------------------------------+----------------------------------------------------+
 | inout float **POINT_SIZE**     | Point size for point drawing.                      |
 +--------------------------------+----------------------------------------------------+
-| in vec4 **CUSTOM0**            |                                                    |
+| in vec4 **CUSTOM0**            | Custom value from vertex primitive.                |
 +--------------------------------+----------------------------------------------------+
-| in vec4 **CUSTOM1**            |                                                    |
+| in vec4 **CUSTOM1**            | Custom value from vertex primitive.                |
 +--------------------------------+----------------------------------------------------+
 
 Fragment built-ins
