title: Swift 5: 'substring(to:)' is deprecated
body: <p>I`m newbie in Swift and  I have simple code, that cut string from the end to special characters "$2F" and returned cutted off string:</p>
  
  <pre><code>    let index2 = favUrlString.range(of: "%2F", options: .backwards)?.lowerBound
      favUrlString = index2.map(favUrlString.substring(to:))!
  </code></pre>
  
  <p>How I have to update this code to Swift 5?</p>