Create 25-secret_messages.java


     * Reads every 10th letter of encodedMessage and returns a string
     * with the letters it reads.
     * @return A message hidden in the garbled text

     * Optional:
     * Decodes the same way as String read() but takes an index to start at.
     * There may be more than one secret message in the garbled text.
     * @return A message hidden in the garbled text starting at startingIndex
     * @param the first indexToRead