xshell: Making Rust a Better Bash

xshell provides a set of cross-platform utilities for writing ergonomic "bash" scripts.

```rust use xshell::{cmd, read_file};

let name = "Julia"; let output = cmd!("echo hello {name}!").read()?; assert_eq!(output, "hello Julia!");

let err = readfile("feeling-lucky.txt").unwraperr(); asserteq!( err.tostring(), "feeling-lucky.txt: no such file or directory (os error 2)", ); ```

See the docs for more.