Rust supports more than AtomicUsize#3

I noticed at the end that you said Rust only supports `usize`-sized atomics, which is incorrect: Rust's standard library supports all of `u8`, `i8`, `u16`, `i16`, `u32`, `i32`, `u64`, and `i64` since v1.34 and `usize`, `isize`, `bool`, and `*mut T` since v1.0. See [`AtomicU8`](https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html) Btw, really liked your article! You might find reading about TileLink interesting, since it is an open-source cache-coherent memory interface used in a lot of RISC-V computers.