title: Implement Document Picker in swift (iOS)
body: <p>I want to pick a file of any type(.pdf, .docs, .xlsx, .jpeg, .txt, .rtf, etc) functionality in my iOS app. On clicking on <strong>Upload</strong> button, I want my app to open a directory and select files(<code>DocumentsPicker</code>)</p>
  
  <pre><code>@IBAction pickDocument(sender: UIButton) {
      //Open Document Picker
  }
  </code></pre>
  
  <p>Any approach to do so in <code>Swift</code>?</p>