rust-hashcash docs

MIT licensed Rust implementation of the hashcash algorithm ported from hashcash.py. Notable differences are that only version 1 of hashcash is supported and sha3 is used as the default hashing algorithm. sha1 is available with a feature flag.

Example

```rust

use rust_hashcash::{Stamp, check};

fn main {

let stamp = Stamp::default();
assert!(check(stamp.to_string()));

}

```

Usage

toml [dependencies] rust-hashcash = "0.1"

With sha1

toml [dependencies] rust-hashcash = {version = "0.1", features=["sha1"]}