Missing documentation
Looking at the docs, it's missing descriptions on all items. Even if many informations about posits themselves can be found around the Internet, it's still worth to document this implementation.
Also, many crates feature at least an minimal documentation with links to standard documents. However, this crate doesn't have even that. Having proper documentation might be secondary on a immature crate but lack of it might discourage people from even trying it out.
This message comes from good will. I simple wanted to try using posits in Rust but missing docs left me confused about what's what in this crate.