feat(cms-core): add Payload config with postgres adapter and lexical editor

packages/cms-core/src/index.ts

@@ -1,2 +1,5 @@
-// @repo/cms-core — Payload CMS config, collections, hooks, globals
-export {};
+export { Users } from "./collections/users/index.js";
+export { Articles } from "./collections/articles/index.js";
+export { Media } from "./collections/media/index.js";
+export { SiteSettings } from "./globals/site-settings.js";
+export { default as config } from "./payload.config.js";