## Description
This PR ensures that the default prettier config is used for examples
and templates.
This config is compatible with `prettier@3` as well (upgrading prettier
is bigger change that can be a future PR).
## Changes
- Updated `.prettierrc.json` in root with `"trailingComma": "es5"` (will
be needed upgrading to prettier@3)
- Added `examples/.prettierrc.json` with default config (this will
change every example)
- Added `packages/create-next-app/templates/.prettierrc.json` with
default config (this will change every template)
## Related
- Fixes#54402
- Closes#54409
Converted example to TypeScript to match Contribution docs.
- Set cookies using `NextResponse` instead of the `Set-Cookie` header
## Documentation / Examples
- [X] Make sure the linting passes by running `pnpm build && pnpm lint`
- [X] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)
### 📖 What's in there?
Middleware matchers are powerful, but very few people realized it, because they are not really documented.
This PR tries to bring more clarity, and includes a more advanced example.
The example shows how to exclude several pages (no `/static`, no `/public`), but also allow specific page in excluded paths (`/public/disclaimer`)
### 🧪 How to test?
Run the example: `pnpm next dev examples/middleware-matcher`, then browse to http://localhost:3000
The first 3 links should not match, the last 3 ones should.
Don't forget to clear your localhost cookies if you change the middleware code.
### 🆙 Note to reviewers
Using session cookies to pass information from middleware to the rendered page is not great, because `document.cookie` is not available during SSR, and because cookies persist when refreshing the page (making it hard to try different matchers)
However, I couldn't find a simpler way to convey the information from the middleware to the page, and I meant to have something visual. The other option is to use response headers and curl commands, but...
