New features on lib.rs

I've implemented a few new things on lib.rs recently! New features page It lists all cargo features that a crate supports. It includes comments from Cargo.toml, neatly formatted as markdown, so you can learn what the features do. Since comments on features are rare, I also search crate's source code for uses of cfg(feature = "…") to give a hint what functions or types are affected by the feature. Cargo has this quirk that all optional dependencies implicitly create features, unless you use a ...