[S360] Revert "[CmdPal][AOT] Replace CommunityToolkit.MarkdownTextBlock with CommunityToolkit.Lab.MarkdownTextBlock (#39974)" (#40055)

This reverts commit 7d257cf00c due to a
security concern involving multiple feeds

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## Summary of the Pull Request

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## PR Checklist

- [ ] **Closes:** #xxx
- [ ] **Communication:** I've discussed this with core contributors
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- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
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src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ContentPage.xaml

@@ -11,21 +11,14 @@
     xmlns:converters="using:CommunityToolkit.WinUI.Converters"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:local="using:Microsoft.CmdPal.UI"
-    xmlns:markdownTextBlockRns="using:CommunityToolkit.WinUI.Controls.MarkdownTextBlockRns"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    xmlns:toolkit="using:CommunityToolkit.Labs.WinUI.MarkdownTextBlock"
+    xmlns:toolkit="using:CommunityToolkit.WinUI.UI.Controls"
     xmlns:viewmodels="using:Microsoft.CmdPal.UI.ViewModels"
     Background="Transparent"
     mc:Ignorable="d">
 
     <Page.Resources>
         <ResourceDictionary>
-            <markdownTextBlockRns:MarkdownThemes
-                x:Key="DefaultMarkdownThemeConfig"
-                H3FontSize="12"
-                H3FontWeight="Normal" />
-            <toolkit:MarkdownConfig x:Key="DefaultMarkdownConfig" Themes="{StaticResource DefaultMarkdownThemeConfig}" />
-
             <StackLayout
                 x:Name="VerticalStackLayout"
                 Orientation="Vertical"
@@ -52,7 +45,10 @@
                 <Grid Margin="0,4,4,4" Padding="12,8,8,8">
                     <toolkit:MarkdownTextBlock
                         Background="Transparent"
-                        Config="{StaticResource DefaultMarkdownConfig}"
+                        Header3FontSize="12"
+                        Header3FontWeight="Normal"
+                        Header3Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                        IsTextSelectionEnabled="True"
                         Text="{x:Bind Body, Mode=OneWay}" />
                 </Grid>
             </DataTemplate>
@@ -67,7 +63,10 @@
                 <Grid>
                     <toolkit:MarkdownTextBlock
                         Background="Transparent"
-                        Config="{StaticResource DefaultMarkdownConfig}"
+                        Header3FontSize="12"
+                        Header3FontWeight="Normal"
+                        Header3Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                        IsTextSelectionEnabled="True"
                         Text="{x:Bind Body, Mode=OneWay}" />
                 </Grid>
             </DataTemplate>