docs(turbopack): Copy over turbopack-trace-server docs (#91111)
**Rendered:** https://github.com/vercel/next.js/blob/dd1cc6fba3cff5fbc38dac3ff4426b481bfcbcb5/contributing/turbopack/tracing.md
This is the content from https://turbopack-rust-docs.vercel.sh/tracing_turbopack.html with some minor updates:
- Use GitHub Flavored Markdown for the warning block
- Some grammar fixes/tweaks
- Add an extra note about `--release` being important
- Add a mention of `pnpm next internal trace`
- Add a link to @timneutkens's youtube video
- Change the filepath from the old confusingly named `.next/trace.log` to `.next/trace-turbopack`
- Add a link to https://trace.nextjs.org/
