patch 9.1.0563: Cannot process any Key event

Problem:  Cannot process any Key event
Solution: Add the KeyInputPre autocmd
          (Shougo Matsushita)

closes: #15182

Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Co-authored-by: K.Takata <kentkt@csc.jp>
Signed-off-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index 23f1cbf..1e9c896 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -1,4 +1,4 @@
-*autocmd.txt*   For Vim version 9.1.  Last change: 2024 Jul 09
+*autocmd.txt*   For Vim version 9.1.  Last change: 2024 Jul 11
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -439,6 +439,8 @@
 |CompleteDone|		after Insert mode completion is done, after clearing
 			info
 
+|KeyInputPre|		just before a key is processed
+
 |User|			to be used in combination with ":doautocmd"
 |SigUSR1|		after the SIGUSR1 signal has been detected
 
@@ -977,6 +979,21 @@
 							*InsertLeave*
 InsertLeave			Just after leaving Insert mode.  Also when
 				using CTRL-O |i_CTRL-O|.  But not for |i_CTRL-C|.
+							*KeyInputPre*
+KeyInputPre			Just before a key is processed. The pattern is
+				matched against a string that indicates the
+				current mode, which is the same as what is
+				returned by `mode(1)`.
+				The |v:char| variable indicates the key typed
+				and can be changed during the event to process
+				a different key.  When |v:char| is not a
+				single character or a special key, the first
+				character is used.
+				The following values of |v:event| are set:
+				   typed	The key is typed or not.
+				It is not allowed to change the text
+				|textlock| or the current mode.
+				{only with the +eval feature}
 							*MenuPopup*
 MenuPopup			Just before showing the popup menu (under the
 				right mouse button).  Useful for adjusting the