Updates UI text

PelotonDataGui/MainWindow.xaml

@@ -21,7 +21,7 @@
             <ColumnDefinition />
             <ColumnDefinition Width="Auto"/>
         </Grid.ColumnDefinitions>
-        <TextBlock  Margin="10,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="3"><Run Text="Enter your Peloton account Username and Password. Then specify the directory to output the data files to and click &quot;Get Data&quot;.  Each workout's data will be downloaded and stored in comma separated values format.  If a workout's file is already present in the output directory, it will not be downloaded again."/><LineBreak/><Run Text="Source can be found at http://www.github.com/cabird/PelotonData"/><LineBreak/><Run Text="Questions/Feature Requests/Bug Reports can be sent to cabird@gmail.com (but this is a side project, so...)"/></TextBlock>
+        <TextBlock  Margin="5,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="3"><Run Text="Enter your Peloton account Username and Password. Then specify the directory to output the data files to and click &quot;Get Data&quot;.  Each workout's data will be downloaded and stored in comma separated values format (suitable to open in Excel).  If a workout's file is already present in the output directory, it will not be downloaded again."/><LineBreak/><Run Text="Source can be found at http://www.github.com/cabird/PelotonData"/><LineBreak/><Run Text="Questions/Feature Requests/Bug Reports can be sent to cabird+peloton@gmail.com (but this is a side project, so...)"/></TextBlock>
         <Label Content="Username" Height="30" Margin="0" VerticalAlignment="Top" Grid.Row="1" Grid.Column="0"/>
         <TextBox Name="UsernameTextBox" HorizontalAlignment="Stretch" Height="24" Margin="0" TextWrapping="Wrap" VerticalAlignment="Center"  Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="2"/>