Fix broken example README.md

[avan-pra]

The example to know how much of the input has been consumed wasn't compiling.

use atoi::FromRadix10;

/// Return the parsed integer and remaining slice if successful.
fn atoi_with_rest<I: FromRadix10>(text: &[u8]) -> Option<(&[u8], I)> {
    match I::from_radix_10(text) {
        (_, 0) => None,
        (n, used) => Some((&[used..], n)),
    }
}

fn main() {
    println!("{:?}", atoi_with_rest::<u32>(b"25aaa"));
}

Fixed it by adding the text variable at the right place (see commit).

(using the above main)

$ cargo run
[...]
Some(([97, 97, 97], 25))

[pacman82]

@avan-pra Thank you!