feat: integrate payload cms to landing page (#25)

* feat: integrate payload cms to landing page

* feat: add payload configuration and update TypeScript target

* fix: update TypeScript paths for payload configuration

* refactor: update config import paths to use local payload.config

* fix: update quotation marks for testimonials to use HTML entities

* fix: include withPayload in Next.js plugins for proper configuration

apps/landing/src/collections/Users.ts

@@ -0,0 +1,13 @@
+import type { CollectionConfig } from 'payload';
+
+export const Users: CollectionConfig = {
+  slug: 'users',
+  admin: {
+    useAsTitle: 'email',
+  },
+  auth: true,
+  fields: [
+    // Email added by default
+    // Add more fields as needed
+  ],
+};