feat: add google manager tag

Author: williarin

.vitepress/config.mts

@@ -5,7 +5,23 @@ export default defineConfig({
   base: '/stochastix-docs/',
   title: "Stochastix",
   description: "High-Performance Quantitative Backtesting Engine",
-  head: [['link', { rel: 'icon', href: '/stochastix-docs/favicon.ico' }]],
+  head: [
+    ['link', { rel: 'icon', href: '/stochastix-docs/favicon.ico' }],
+    [
+      'script',
+      {},
+      `(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+      new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+      j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+      'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+      })(window,document,'script','dataLayer','GTM-MR9GH7X4');`
+    ],
+    [
+      'noscript', {}, `
+      <iframe src="https://www.googletagmanager.com/ns.html?id=GTM-MR9GH7X4"
+      height="0" width="0" style="display:none;visibility:hidden"></iframe>`
+    ],
+  ],
   lastUpdated: true,
   themeConfig: {
     logo: '/logo.svg',