minor changes to modern IO article

[danthe1st]

This PR makes minor changes to the modern IO article which has been written by @cayhorstmann in #66.

These changes include:

• using a try-with-resources block to the InputStream#transferTo example.
• fixing a typo in the following sentence:

  Two Files.newDirectoryStream methods yields DirectoryStream instances, which can be used in enhanced for loops. There is no advantage over using Files.list.

• adding a last_review timestamp. I didn't change the last_update because I didn't make significant content changes.

[ammbra]

Looks good to me. Thank you, Dan.

[danthe1st]

(fixed merge conflicts - diff before and after should be the same)