feat: add SignupPromo component

components/HotelReservation/SignupPromo/Mobile.tsx

@@ -0,0 +1,20 @@
+"use client"
+
+import { useIntl } from "react-intl"
+
+import Footnote from "@/components/TempDesignSystem/Text/Footnote"
+
+import styles from "./signupPromo.module.css"
+
+export default function SignupPromoMobile() {
+  const intl = useIntl()
+  return (
+    <div className={styles.memberDiscountBannerMobile}>
+      <Footnote color="burgundy">
+        {intl.formatMessage({
+          id: "Join or log in while booking for member pricing.",
+        })}
+      </Footnote>
+    </div>
+  )
+}