Update sitemap with new audio guides

Author: TechStack Global

sitemap.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version='1.0' encoding='utf-8'?>
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
   <url>
     <loc>https://techstackglobal.github.io/about.html</loc>
@@ -228,4 +228,4 @@
     <changefreq>monthly</changefreq>
     <priority>0.8</priority>
   </url>
-</urlset>
+</urlset>