Clarify transform inheritance of CanvasItem nodes

Author: KoBeWi

doc/classes/CanvasItem.xml

@@ -8,6 +8,7 @@
 		Any [CanvasItem] can draw. For this, [method queue_redraw] is called by the engine, then [constant NOTIFICATION_DRAW] will be received on idle time to request a redraw. Because of this, canvas items don't need to be redrawn on every frame, improving the performance significantly. Several functions for drawing on the [CanvasItem] are provided (see [code]draw_*[/code] functions). However, they can only be used inside [method _draw], its corresponding [method Object._notification] or methods connected to the [signal draw] signal.
 		Canvas items are drawn in tree order on their canvas layer. By default, children are on top of their parents, so a root [CanvasItem] will be drawn behind everything. This behavior can be changed on a per-item basis.
 		A [CanvasItem] can be hidden, which will also hide its children. By adjusting various other properties of a [CanvasItem], you can also modulate its color (via [member modulate] or [member self_modulate]), change its Z-index, blend mode, and more.
+		Note that properties like transform, modulation, and visibility are only propagated to [i]direct[/i] [CanvasItem] child nodes. If there is a non-[CanvasItem] node in between, like [Node] or [AnimationPlayer], the [CanvasItem] nodes below will have an independent position and [member modulate] chain. See also [member top_level].
 	</description>
 	<tutorials>
 		<link title="Viewport and canvas transforms">$DOCS_URL/tutorials/2d/2d_transforms.html</link>