docs: fix analytics tracking.

Author: schettino72

doc/_templates/base.html

@@ -0,0 +1,15 @@
+{% extends "furo/base.html" %}
+
+{% block scripts %}
+  {{ super() }}
+  {% if include_analytics %}
+    <!-- Google Analytics 4 -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-MC3XWQDL4K"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+      gtag('config', 'G-MC3XWQDL4K');
+    </script>
+  {% endif %}
+{% endblock %}