runtime(doc): Update doc 52.6

Problem: the highlight-yank plugin exmaple provided in the doc behaves
	 incorrectly when selection is set to exclusive.

Solution: use a unified offset of 1 and pass 'exclusive: false' to
	  getregionpos(), while at it, also clarify when the
          TextYankPost autocommand triggers.

closes: #16866

Signed-off-by: Jim Zhou <jimzhouzzy@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index 5c44958..8532fc9 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -1,4 +1,4 @@
-*autocmd.txt*   For Vim version 9.1.  Last change: 2025 Mar 08
+*autocmd.txt*   For Vim version 9.1.  Last change: 2025 Mar 12
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1346,6 +1346,10 @@
 				called recursively.
 				It is not allowed to change the buffer text,
 				see |textlock|. *E1064*
+				Also triggered indirectly when Vim tries to
+				become owner of the Visual selection because
+				of setting "autoselect" for 'guioptions' or
+				'clipboard'.
 				{only when compiled with the +eval feature}
 
 							*User*