no_std documentation does not appear on docs.rs

[bradleyharden]

This isn't a huge deal, but I wanted to point out that the documentation for no_std only appears on crates.io and on GitHub. It does not appear on docs.rs. However, I would expect docs.rs to be the primary entry point for newcomers discovering this crate. I think it might be helpful if to add it there as well. There are some really important things to consider in a no_std context.

Thanks for providing this crate, by the way. It's been exactly what I needed in a handful of cases.