Moved code into src folder. Added build for component library.

src/pages/reports/retention.js

@@ -0,0 +1,13 @@
+import AppLayout from 'components/layout/AppLayout';
+import RetentionReport from 'components/pages/reports/retention/RetentionReport';
+import useMessages from 'components/hooks/useMessages';
+
+export default function () {
+  const { formatMessage, labels } = useMessages();
+
+  return (
+    <AppLayout title={`${formatMessage(labels.retention)} - ${formatMessage(labels.reports)}`}>
+      <RetentionReport />
+    </AppLayout>
+  );
+}