title: How to set model data from QML?
body: <p>In C++ we can use <code>QAbstractItemModel::setData()</code> to modify the model's data. Searching the internet I only found how to read data from model to display it in a delegate. There are also some examples of adding and removing rows, but I could not find how to change the data of specific model index. Something like:</p>
  
  <pre><code>Slider {
      onValueChanged: myModel.setData(0, {amount: value})
  }
  </code></pre>
  
  <p>How can I modify data in a model from in QML?</p>