runtime(doc): add help tag describing object-selection

closes: #13114

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/motion.txt b/runtime/doc/motion.txt
index 2ddd1b9..c89eead 100644
--- a/runtime/doc/motion.txt
+++ b/runtime/doc/motion.txt
@@ -1,4 +1,4 @@
-*motion.txt*    For Vim version 9.0.  Last change: 2022 Sep 26
+*motion.txt*    For Vim version 9.0.  Last change: 2023 Sep 18
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -683,6 +683,7 @@
 			Special case: With a count of 2 the quotes are
 			included, but no extra white space as with a"/a'/a`.
 
+							*o_object-select*
 When used after an operator:
 For non-block objects:
 	For the "a" commands: The operator applies to the object and the white
@@ -698,6 +699,7 @@
 	the surrounding braces are excluded.  For the "a" commands, the braces
 	are included.
 
+							*v_object-select*
 When used in Visual mode:
 When start and end of the Visual area are the same (just after typing "v"):
 	One object is selected, the same as for using an operator.