change ads.txt to head.html

Author: ppippi-dev

_includes/head.html

@@ -50,4 +50,8 @@
 		gtag('config', '{{ site.theme_settings.google_analytics }}');
 	</script>
 	{% endif %}
+
+	<script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-4845852016760480"
+     crossorigin="anonymous"></script>
+
 </head>