improve drawer content sample. fixes #223 [skip ci]

Author: ButchersBoy

MainDemo.Wpf/MainWindow.xaml

@@ -38,8 +38,9 @@
     <materialDesign:DialogHost Identifier="RootDialog">
         <materialDesign:DrawerHost IsLeftDrawerOpen="{Binding ElementName=MenuToggleButton, Path=IsChecked}">
             <materialDesign:DrawerHost.LeftDrawerContent>
-                <StackPanel Orientation="Vertical">
+                <DockPanel MinWidth="212">
                     <ToggleButton Style="{StaticResource MaterialDesignHamburgerToggleButton}" 
+                                  DockPanel.Dock="Top"
                                   HorizontalAlignment="Right" Margin="16"
                                   IsChecked="{Binding ElementName=MenuToggleButton, Path=IsChecked, Mode=TwoWay}" />
                     <ListBox x:Name="DemoItemsListBox" Margin="0 16 0 16" SelectedIndex="0"                         
@@ -168,7 +169,7 @@
                             </domain:DemoItem.Content>
                         </domain:DemoItem>
                     </ListBox>
-                </StackPanel>
+                </DockPanel>
             </materialDesign:DrawerHost.LeftDrawerContent>
             <DockPanel>
                 <materialDesign:ColorZone Padding="16" materialDesign:ShadowAssist.ShadowDepth="Depth2"