Set font weight to bold on primary action button

Author: donokuda

src/GitHub.VisualStudio/Styles/Buttons.xaml

@@ -96,6 +96,7 @@
         <Setter Property="BorderBrush" Value="{DynamicResource GitHubPrimaryButtonBorderBrush}" />
         <Setter Property="Foreground" Value="{DynamicResource GitHubPrimaryButtonForegroundBrush}" />
         <Setter Property="FontFamily" Value="{DynamicResource GitHubFontFamilyNormal}" />
+        <Setter Property="FontWeight" Value="Bold" />
         <Setter Property="Padding" Value="12,5" />
         <Setter Property="Margin" Value="0" />
         <Setter Property="MinWidth" Value="76" />