Upload to crates.io

Hey,

I am looking for a softfloat library for a multi-system pure Rust emulator I am working on (RISC-V 32 bit, RISC-V 64 bit, Cortex-M with more planned for the future).

I looked into various libraries, and yours seems like the best fit:
- No usage of globals, so it's multi-thread safe
- Pure Rust, so it doesn't slow down / complicate the build unnecessarily

My main issue at this point: Would you be interested in publishing on crates.io? I prefer to pull from there vs. a Github project.

I'd also be very interested in 16 and 128 bit support in the future (and I saw there's already a PR open for that - hope that can be merged). But for now, 32 and 64 bit would be a great start already.

Having some automated tests would also be great - I'd love to push patches for whatever I find in the future (e.g. if armv7m requires some non-standard features).

Thanks!