Feature description

Support for complex numbers in tensors.

Feature motivation

I saw your presentation on Scientific Computing in Rust and come to know burn. As I skim through the doc and issue list, it seems there's no complex number support yet. I'm writing some code for quantum computing simulation, and it'd be super cool to writing it in Rust, but I need complex numbers.

(Optional) Suggest a Solution

Perhaps we can add the most simplistic support for it by treating a complex number as a 2D vector with specific ops.