feat: hide intercom behind feature flag

Author: ngnijland

docs/src/layouts/components/Intercom.astro

@@ -1,7 +1,9 @@
 <script is:inline>
+  var isPreview = localStorage.getItem("intercom_preview") === "true";
   window.intercomSettings = {
     api_base: "https://api-iam.intercom.io",
     app_id: "wbadhzkf",
+    hide_default_launcher: !isPreview,
   };
 </script>
 <script is:inline>