title: How to save to more JSON data to a already created file?
body: <p>So i followed this tutorial here: <code>http://developer.xamarin.com/recipes/ios/general/file_system/save_documents/</code> and everything works fine but the only thing is that once a file is created that has JSON saved to it i want to be table to add a some more JSON data</p>
  
  <p>right now i am using JSON.net to Serialize my data and saving it to a file</p>
  
  <pre><code>var documents = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
  var filename = Path.Combine (documents, "Settings.txt");
  
  File.WriteAllText(filename, "Write this text into a file!");
  </code></pre>
  
  <p>Just Do not know how to add more data to the already existing data</p>