feat: add landing page for mobile viewport

apps/gacha/src/app/page.tsx

@@ -1,7 +1,13 @@
+import { LandingPage } from '@imphnen-frontend-service/ui/organisms';
 import { FC, ReactElement } from 'react';
 
 export const Components: FC = (): ReactElement => {
-  return <>Hallo</>;
+  return (
+    <>
+      <LandingPage />
+      <div></div>
+    </>
+  );
 };
 
 export default Components;