Update error doc for CSS Modules in third-party deps (#46121)

Fixes NEXT-355



## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] [e2e](https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs) tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm build && pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

errors/css-modules-npm.md

@@ -21,4 +21,8 @@ imported by you, in your application.
 ---
 
 If this is **first party code**, try
-[including said monorepo package in the compilation pipeline](https://github.com/vercel/next.js/tree/canary/examples/with-yarn-workspaces).
+[including monorepo packages in the compilation pipeline](https://nextjs.org/docs/advanced-features/compiler#module-transpilation).
+
+---
+
+This limitation does not exist when using the `app` directory: [beta.nextjs.org/docs](https://beta.nextjs.org/docs).