feat: integrate payload cms to landing page

apps/landing/src/app/(payload)/api/graphql-playground/route.ts

@@ -0,0 +1,7 @@
+/* THIS FILE WAS GENERATED AUTOMATICALLY BY PAYLOAD. */
+/* DO NOT MODIFY IT BECAUSE IT COULD BE REWRITTEN AT ANY TIME. */
+import config from '@payload-config';
+import '@payloadcms/next/css';
+import { GRAPHQL_PLAYGROUND_GET } from '@payloadcms/next/routes';
+
+export const GET = GRAPHQL_PLAYGROUND_GET(config);