Update .cargo/config.toml in setup to match .cargo/config.toml at the root of the book

[Tomer-Eliahu]

While the discovery book suggests you clone the book repo, I prefer working gradually and only copying files when I need them.

I copied just the setup files and got the error:

WARN probe_rs::flashing::loader: No loadable segments were found in the ELF file.
Error No loadable segments were found in the ELF file.

This error probably does not happen if you clone the whole book repo (I guess then cargo uses the root config over the setup config), but adding "-C", "link-arg=-Tlink.x" to the rustflags prevents this error.

[BartMassey]

I am unable to reproduce the problem: if I copy 03-setup to a temp directory outside the workspace and build it as is, it works fine. That said, it works fine for me with the change as well, so we'll take your fix and see if it causes anyone an issue, I think..

I suspect it's a platform difference. I'm on Linux: you?

Let us know if 05-meet-your-software and beyond have the same issue.

Thanks much for the contribution!