Display build target with the j5s version (eg. intel vs apple silicon)

[nevadascout]

https://doc.rust-lang.org/cargo/reference/build-script-examples.html

Shouldn't be too hard -- create a build.rs file that can get the target architecture and write it as a hardcoded string into a new module in the out directory for use inside the app.

Use the include! macro to import it where we want to use it.