fix: Replace "syntax" with "xml" code fences

Used find/replace regex in VS Code
Find:``` syntax(\s\n*)<\?xml
Replace:```xml$1<?xml

windows/deployment/usmt/usmt-configxml-file.md

@@ -383,7 +383,7 @@ Syntax: `<exclude>`` </exclude>`
 
 Refer to the following sample Config.xml file for additional details about items you can choose to exclude from a migration.
 
-``` syntax
+```xml
 <?xml version="1.0" encoding="UTF-8"?>
 <Configuration>
   <Applications/>