code: func Ljust(strs []string) []string {
  	llen := len(Longest(strs))
  
  	dup := make([]string, len(strs), cap(strs))
  	copy(dup, strs)
  
  	for i, str := range strs {
  		width := MaxInt(0, llen-len(str))
  		padding := strings.Repeat(" ", width)
  
  		dup[i] = str + padding
  	}
  
  	return dup
  }
docs: // Ljust returns a copied string slice where each element is left justified to
  // match the width of the longest element in the set.