Add back Google Analytics

frontend/src/tracking.js

@@ -0,0 +1,15 @@
+
+import { useEffect } from "react";
+import { useLocation } from "react-router-dom";
+
+export const usePageTracking = () => {
+  const location = useLocation();
+
+  useEffect(() => {
+    window.gtag("event", "page_view", {
+      page_path: location.pathname + location.search + location.hash,
+      page_search: location.search,
+      page_hash: location.hash,
+    });
+  }, [location]);
+};