Manual: Document that capture refiling is sensitive to the cursor position

* doc/org.texi (Using capture): Explain that refiling is sensitive
to cursor position.

doc/org.texi

@@ -5968,7 +5968,10 @@ process, so that you can resume your work without further distraction.
 @kindex C-c C-w
 @item C-c C-w
 Finalize the capture process by refiling (@pxref{Refiling notes}) the note to
-a different place.
+a different place.  Please realize that this is a normal refiling command
+that will be executed - so the cursor position at the moment you run this
+command is important.  If you have inserted a tree with a parent and
+children, first move the cursor back to the parent.
 
 @kindex C-c C-k
 @item C-c C-k