Extended PathBuf

Here are some examples on how to use it:

let path = Path::new("C:\\Users\\user\\Desktop\\test.txt"); let path = path.replace("user/Desktop", "user/Documents"); assert_eq!(path, PathBuf::from("C:\\Users\\user\\Documents\\test.txt"));

``` let path = Path::new("C:\Users\user\Desktop\test.txt"); assert!(path.contains("Desktop")); assert!(!path.contains("Documents"));

// Windows assert!(path.contains("user\Desktop")); assert!(!path.contains("user\Documents"));

// Linux assert!(path.contains("user/Desktop")); assert!(!path.contains("user/Documents")); ```