Add a option for root element, put xmlns:* in sperate lines #329

Is your feature request related to a problem? Please describe.
It's not a problem.
I just like the format like following style:

<Window x:Class="Xxxx.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:local="Xxxx"
        xmlns:xxx="http://xxxx"
        Width="200" Height="100" FontSize="15"
        FontWeight="Bold" Xxxx="xxxx">
    <Lable Content="Test" Margin="10 10 10 10" Grid.Row="1"/>
</Window>

Describe the solution you'd like
Add a option for root element, format xmlns:* in sperate lines

Describe alternatives you've considered
I think the rule of formatting root element can be different as other elements.