Fix benchmark link typo in Turbopack example (vercel#42064)

Author: iiegor

Diff for: examples/with-turbopack/README.md

@@ -1,6 +1,6 @@
 # Next.js + Turbopack App Directory Playground
 
-[Turbopack](https://turbo.build/pack) is a new incremental bundler optimized for JavaScript and TypeScript, written in Rust by the creators of Webpack and Next.js at [Vercel](https://vercel.com). On large applications Turbopack updates 10x faster than Vite and 700x faster than Webpack ([benchmark](https://turbo.build/pack/pack/docs/benchmarks)). For the biggest applications the difference grows even more stark with updates up to 20x faster than Vite.
+[Turbopack](https://turbo.build/pack) is a new incremental bundler optimized for JavaScript and TypeScript, written in Rust by the creators of Webpack and Next.js at [Vercel](https://vercel.com). On large applications Turbopack updates 10x faster than Vite and 700x faster than Webpack ([benchmark](https://turbo.build/pack/docs/benchmarks)). For the biggest applications the difference grows even more stark with updates up to 20x faster than Vite.
 
 This playground is a mirror of the [Next.js v13 App Directory Playground](https://github.com/vercel/app-playground), but uses Turbopack as the Next.js development server (`next dev --turbo`).