`deno pack` CLI reference does not match Deno 2.9 behaviour

https://github.com/denoland/deno/pull/35331 (included in the 2.9 release) changed the behaviour of the `deno pack` subcommand, so that all files included by `deno publish` are also included in the npm tarball. This is obviously quite a bit more than what is documented in the [What's in the tarball](https://docs.deno.com/runtime/reference/cli/pack/#what's-in-the-tarball) section of the `deno pack` CLI reference page.

Open the `deno pack` CLI reference and review the “What’s in the tarball” section linked in the issue. Compare its description with the Deno 2.9 behavior described here, then update the documentation so it covers all files included by `deno publish`; verify the rendered page reflects the changed behavior.

Written by the indexing model from the issue text.