Bootstrap basic Rust CI

[notfilippo]

Once #1 is merged we should follow it up with a PR to enable GitHub actions to run some basic Rust checks for formatting, clippy checks and tests.

[tisonkun]

In fast/template I developed a cargo xtask based solution for smooth dev. But if that looks too heavy, fast/logforth provides a reference GHA workflow with built-in cargo commands.

[notfilippo]

Nice! I think I like the fast/logforth approach better.

[tisonkun]

A patch for it is now #13