title: Redirect to old website version when not found
body: <p>I have a website (ex. at chamthi.net).
  I lance new version of the website, and old version (articles) has been moved to <strong>/old</strong> directory (<strong>chamthi.net/old</strong>).
  I want each time a user go to a url that is currently not available (404), the website will redirect user to old version.
  Is there any solution for that?
  Thanks.</p>