v2.4.0

• add copy() method.

• add ability to extend Strings class with Macros.

  use Atomastic\Strings\Strings;
  use Atomastic\Macroable\Macroable;
  
  Strings::macro('concatenate', function(string $string) {
      return $this->toString() . $string;
  });
  
  $strings = new Strings('Hello');
  
  echo $strings->concatenate(' World'));