Feat: Import all old stuff

theme/templates/partial/gtm.html

@@ -0,0 +1,12 @@
+<!-- Google Tag Manager -->
+<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','{{ GOOGLE_TAG_MANAGER }}');
+</script>
+<!-- End Google Tag Manager -->