broken rust docs

Hi,

Rust Docs are broken for several previous versions of this crate, especially the 0.9 and 0.8 series.

https://docs.rs/crate/rsa/0.9.9

https://crates.io/crates/rsa/0.8.2

Would you kindly publish patch versions that fix the docs for these series? In order to help developers rewrite their code to migrate closer to the latest rsa crate version.