title: How to place instance of window in LayoutAnchorable AvalonDock 2
body: <p>I'm upgrading AvalonDock in a WPF C# application (not MVVM) from 1.3 to 2.0. In 1.3 I was able to place custom windows as long as used DockableContent:
  XAML:</p>
  
  <pre><code>&lt;!--&lt;Window--&gt;
  &lt;ad:DockableContent   x:Class="Test.JournalWindow"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:ad="clr-namespace:AvalonDock;assembly=AvalonDock" 
          xmlns:local="clr-namespace:Test"
          xmlns:sys="clr-namespace:System;assembly=mscorlib"
  
          Loaded="Journal_Loaded" StateChanged="Journal_StateChanged"
          Title="Journal" Icon = "Resources/journalLog.ico" HideOnClose="True" Height="300" Width="Auto"&gt;
  
      &lt;ad:DockableContent.Resources&gt;
        &lt;/ad:DockableContent.Resources&gt;
  
                  &lt;Grid&gt;  &lt;/Grid&gt;
  &lt;/ad:DockableContent&gt;
  &lt;!--&lt;/Window&gt;--&gt;
  </code></pre>
  
  <p>Code Behind:</p>
  
  <pre><code>public partial class JournalWindow : DockableContent
      {
          public JournalWindow()
          {
              InitializeComponent();
          }
  </code></pre>
  
  <p>Code in MainWindow to display instantited element:</p>
  
  <pre><code>JournalWindow journalWindow;
   journalWindow = new JournalWindow()
              {
                  Name = nameJournalWindow,
                  Title = "Journal"
              };
  
              journalWindow.IsCloseable = true;
              journalWindow.HideOnClose = true;
              journalWindow.Show(dockManager);
  </code></pre>
  
  <p>How to place and show instance of JournalWindow in LayoutAnchorable or other layout element (previously as DockableContent) using AvalonDock 2 ?</p>