add: Clarity tracking code

src/layouts/Layout.astro

@@ -113,6 +113,14 @@ const rssHref = getRelativeLocaleUrl(
         window.__theme = { value: theme };
       })();
     </script>
+    <!-- Clarity tracking code for https://qihanx.cn/ -->
+    <script>
+      (function(c,l,a,r,i,t,y){
+        c[a]=c[a]||function(){(c[a].q=c[a].q||[]).push(arguments)};
+        t=l.createElement(r);t.async=1;t.src="https://www.clarity.ms/tag/"+i+"?ref=bwt";
+        y=l.getElementsByTagName(r)[0];y.parentNode.insertBefore(t,y);
+      })(window, document, "clarity", "script", "y0in01zh7v");
+    </script>
 
     <ClientRouter />
   </head>