patch 8.2.2440: documentation based on patches is outdated

Problem:    Documentation based on patches is outdated.
Solution:   Add changes to documentation in a patch.
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index dfd7dcb..20a8f4b 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -1,4 +1,4 @@
-*autocmd.txt*   For Vim version 8.2.  Last change: 2020 Dec 19
+*autocmd.txt*   For Vim version 8.2.  Last change: 2021 Jan 28
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -54,7 +54,8 @@
 :au[tocmd] [group] {event} {pat} [++once] [++nested] {cmd}
 			Add {cmd} to the list of commands that Vim will
 			execute automatically on {event} for a file matching
-			{pat} |autocmd-patterns|.
+			{pat} |autocmd-patterns|. 
+			Here {event} cannot be "*".  *E1155*
 			Note: A quote character is seen as argument to the
 			:autocmd and won't start a comment.
 			Vim always adds the {cmd} after existing autocommands,