patch 9.1.0464: no whitespace padding in commentstring option in ftplugins

Problem:  no whitespace padding in commentstring option in ftplugins
Solution: Change default to include whitespace padding, update
          existing filetype plugins with the new default value
          (Riley Bruins)

closes: #14843

Signed-off-by: Riley Bruins <ribru17@hotmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/xml.vim b/runtime/ftplugin/xml.vim
index b81c398..83c528e 100644
--- a/runtime/ftplugin/xml.vim
+++ b/runtime/ftplugin/xml.vim
@@ -3,6 +3,7 @@
 "   Maintainer:	Christian Brabandt <cb@256bit.org>
 " Last Changed: Dec 07th, 2018
 "		2024 Jan 14 by Vim Project (browsefilter)
+"		2024 May 23 by Riley Bruins <ribru17@gmail.com> ('commentstring')
 "   Repository: https://github.com/chrisbra/vim-xml-ftplugin
 " Previous Maintainer:	Dan Sharp
 "          URL:		      http://dwsharp.users.sourceforge.net/vim/ftplugin
@@ -15,7 +16,7 @@
 let s:save_cpo = &cpo
 set cpo&vim
 
-setlocal commentstring=<!--%s-->
+setlocal commentstring=<!--\ %s\ -->
 " Remove the middlepart from the comments section, as this causes problems:
 " https://groups.google.com/d/msg/vim_dev/x4GT-nqa0Kg/jvtRnEbtAnMJ
 setlocal comments=s:<!--,e:-->