runtime(comment): include a simple comment toggling plugin

fixes #14626
closes: #14634

Signed-off-by: Maxim Kim <habamax@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/tags

@@ -6515,6 +6515,7 @@ command-block	vim9.txt	/*command-block*
 command-line-functions	usr_41.txt	/*command-line-functions*
 command-line-window	cmdline.txt	/*command-line-window*
 command-mode	intro.txt	/*command-mode*
+comment-install	usr_05.txt	/*comment-install*
 compatible-default	starting.txt	/*compatible-default*
 compile-changes-5	version5.txt	/*compile-changes-5*
 compile-changes-6	version6.txt	/*compile-changes-6*

runtime/doc/usr_05.txt

@@ -1,4 +1,4 @@
-*usr_05.txt*	For Vim version 9.1.  Last change: 2023 Sep 12
+*usr_05.txt*	For Vim version 9.1.  Last change: 2024 Apr 26
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -436,6 +436,18 @@ when Vim starts, add the following line to your vimrc file: >
 After restarting your Vim, the plugin is active and you can read about it at: >
 	:h editorconfig.txt
 
+
+Adding comment package					*comment-install*
+
+Load the plugin with this command: >
+    packadd comment
+<
+This way you can use the plugin with the default key bindings `gc` and similar
+for commenting (which is a well-established mapping in the Vim community).
+
+After restarting your Vim, the plugin is active and you can read about it at: >
+	:h comment.txt
+
 More information about packages can be found here: |packages|.
 
 ==============================================================================

runtime/doc/version9.txt

@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2024 Apr 14
+*version9.txt*  For Vim version 9.1.  Last change: 2024 Apr 26
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41554,6 +41554,7 @@ Enum support for Vim9 script |:enum|
 
 Other improvements				*new-other-9.2*
 ------------------
+The comment plugin |comment-install| is included.
 
 Changed						*changed-9.2*
 -------