add some basic crate docs (#55)

Author: seanmonstar

README.md

@@ -1,3 +1,7 @@
 # hyper-util
 
-A collection of utilities to be do common things with hyper.
+A collection of utilities to do common things with [hyper](https://hyper.rs).
+
+## License
+
+This project is licensed under the [MIT license](./LICENSE).

src/lib.rs

@@ -1,7 +1,10 @@
 #![deny(missing_docs)]
 #![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]
 
-//! hyper-util
+//! Utilities for working with hyper.
+//!
+//! This crate is less-stable than [`hyper`](https://docs.rs/hyper). However,
+//! does respect Rust's semantic version regarding breaking changes.
 
 #[cfg(feature = "client")]
 pub mod client;