Convert string to number after removing whitespaces

---

examples/convert/string-to-int-trim/src/main.rs

fn main() {
    let text = "23\n";
    println!("'{}'", text);
    let number: i32 = text.trim().parse().expect("Could not convert to i32");

    println!("'{}'", number);
    println!("'{}'", number + 1);
}

'23
'
'23'
'24'