Update runtime files
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 0a3e319..17d4b85 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -1,4 +1,4 @@
-*syntax.txt*	For Vim version 9.0.  Last change: 2022 Nov 06
+*syntax.txt*	For Vim version 9.0.  Last change: 2022 Nov 15
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1888,6 +1888,16 @@
 Now you just need to make sure that you add all regions that contain
 the preprocessor language to the cluster htmlPreproc.
 
+							*html-folding*
+The HTML syntax file provides syntax |folding| (see |:syn-fold|) between start
+and end tags.  This can be turned on by >
+
+	:let g:html_syntax_folding = 1
+	:set foldmethod=syntax
+
+Note: Syntax folding might slow down syntax highlighting significantly,
+especially for large files.
+
 
 HTML/OS (by Aestiva)				*htmlos.vim* *ft-htmlos-syntax*
 
@@ -5394,8 +5404,8 @@
 MatchParen	Character under the cursor or just before it, if it
 		is a paired bracket, and its match. |pi_paren.txt|
 							*hl-MessageWindow*
-MessageWindow	Messages popup window used when 'cmdheight' is zero.  If not
-		defined |hl-WarningMsg| is used.
+MessageWindow	Messages popup window used by `:echowindow`.  If not defined
+		|hl-WarningMsg| is used.
 							*hl-ModeMsg*
 ModeMsg		'showmode' message (e.g., "-- INSERT --").
 							*hl-MoreMsg*