title: add widgets to qt-creator designer
body: <p>I'm new to using Qt and many of the tutorials I read online demonstrated on how to develop a simple web browser. I'm using Qt Creator as the IDE.</p>
  <p>The problem I'm facing is that in the designer of Qt Creator there is no WebView or any other web widget for me to drag and drop. Earlier even .pro file and .cpp files were giving errors when I typed QT += webkit or included QtWebKit library in them respectively. But then I ran</p>
  <pre><code>sudo apt-get install libqt5webkit5-dev
  </code></pre>
  <p>on the terminal and .pro and .cpp stopped giving those errors. But I still can't figure out how to add widgets to the designer.</p>
  <p>My Qt Creator version is <code>3.1.1</code> and Qt version is <code>5.2.1</code>.</p>