Remove parsers (#3759)

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## Fixes #3744
<!-- Add the relevant issue number after the "#" mentioned above (for ex: Fixes #1234) which will automatically close the issue once the PR is merged. -->

<!-- Add a brief overview here of the feature/bug & fix. --> 
Move Parsing code from `Microsoft.Toolkit.Parsers` into `Microsoft.Toolkit.Uwp.UI.Controls.Markdown`. Make parsing code internal as we don't want anyone using our parsers. 

Remove sample `MarkdownParserPage` as it directly uses our parser.


## PR Type
What kind of change does this PR introduce?
<!-- Please uncomment one or more that apply to this PR. -->

<!-- - Bugfix -->
<!-- - Feature -->
<!-- - Code style update (formatting) -->
- Refactoring (no functional changes, no api changes)
<!-- - Build or CI related changes -->
<!-- - Documentation content changes -->
- Sample app changes
<!-- - Other... Please describe: -->


## What is the current behavior?
<!-- Please describe the current behavior that you are modifying, or link to a relevant issue. -->


## What is the new behavior?
<!-- Describe how was this issue resolved or changed? -->


## PR Checklist

Please check if your PR fulfills the following requirements:

- [ ] Tested code with current [supported SDKs](../readme.md#supported)
- [ ] Pull Request has been submitted to the documentation repository [instructions](..\contributing.md#docs). Link: <!-- docs PR link -->
- [ ] Sample in sample app has been added / updated (for bug fixes / features)
    - [ ] Icon has been created (if new sample) following the [Thumbnail Style Guide and templates](https://github.com/windows-toolkit/WindowsCommunityToolkit-design-assets)
- [ ] New major technical changes in the toolkit have or will be added to the [Wiki](https://github.com/windows-toolkit/WindowsCommunityToolkit/wiki) e.g. build changes, source generators, testing infrastructure, sample creation changes, etc...
- [ ] Tests for the changes have been added (for bug fixes / features) (if applicable)
- [ ] Header has been added to all new source files (run *build/UpdateHeaders.bat*)
- [ ] Contains **NO** breaking changes

<!-- If this PR contains a breaking change, please describe the impact and migration path for existing applications below. 
     Please note that breaking changes are likely to be rejected within minor release cycles or held until major versions. -->


## Other information

Author: msftbot[bot]

Microsoft.Toolkit.Parsers/Microsoft.Toolkit.Parsers.csproj

@@ -25,6 +25,7 @@ namespace Microsoft.Toolkit.Uwp.SampleApp.Controls
     /// </summary>
     internal class SampleAppMarkdownRenderer : MarkdownRenderer
     {
+#pragma warning disable CS0618 // Type or member is obsolete
         public SampleAppMarkdownRenderer(MarkdownDocument document, ILinkRegister linkRegister, IImageResolver imageResolver, ICodeBlockResolver codeBlockResolver)
             : base(document, linkRegister, imageResolver, codeBlockResolver)
         {
@@ -514,5 +515,6 @@ private class CustomCodeBlock
 
             public string CurrentLanguage { get; set; }
         }
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 }

Microsoft.Toolkit.Uwp.SampleApp/Controls/SampleAppMarkdownRenderer.cs

@@ -745,9 +745,6 @@
     <Compile Include="SamplePages\ListViewExtensions\ListViewExtensionsPage.xaml.cs">
       <DependentUpon>ListViewExtensionsPage.xaml</DependentUpon>
     </Compile>
-    <Compile Include="SamplePages\MarkdownParser\MarkdownParserPage.xaml.cs">
-      <DependentUpon>MarkdownParserPage.xaml</DependentUpon>
-    </Compile>
     <Compile Include="SamplePages\Menu\Commands\VsCommands.cs" />
     <Compile Include="SamplePages\Menu\MenuPage.xaml.cs">
       <DependentUpon>MenuPage.xaml</DependentUpon>
@@ -1175,10 +1172,6 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
-    <Page Include="SamplePages\MarkdownParser\MarkdownParserPage.xaml">
-      <SubType>Designer</SubType>
-      <Generator>MSBuild:Compile</Generator>
-    </Page>
     <Page Include="SamplePages\Mouse\MouseCursorPage.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
@@ -1401,10 +1394,6 @@
     </Page>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\Microsoft.Toolkit.Parsers\Microsoft.Toolkit.Parsers.csproj">
-      <Project>{42CA4935-54BE-42EA-AC19-992378C08DE6}</Project>
-      <Name>Microsoft.Toolkit.Parsers</Name>
-    </ProjectReference>
     <ProjectReference Include="..\Microsoft.Toolkit.Uwp.Connectivity\Microsoft.Toolkit.Uwp.Connectivity.csproj">
       <Project>{b1e850ff-dde6-44d5-a830-34250e97a687}</Project>
       <Name>Microsoft.Toolkit.Uwp.Connectivity</Name>

Microsoft.Toolkit.Uwp.SampleApp/Microsoft.Toolkit.Uwp.SampleApp.csproj

@@ -857,14 +857,6 @@
         "Icon": "/Assets/Helpers.png",
         "DocumentationUrl": "https://raw.githubusercontent.com/MicrosoftDocs/WindowsCommunityToolkitDocs/master/docs/behaviors/FocusBehavior.md"
       },
-      {
-        "Name": "Markdown Parser",
-        "Type": "MarkdownParserPage",
-        "Subcategory": "Parser",
-        "About": "The Markdown Parser allows you to parse a Markdown String into a Markdown Document, and then Render it with a Markdown Renderer.",
-        "Icon": "/Assets/Helpers.png",
-        "DocumentationUrl": "https://raw.githubusercontent.com/MicrosoftDocs/WindowsCommunityToolkitDocs/master/docs/parsers/MarkdownParser.md"
-      },
       {
         "Name": "Win2d Path Mini Language Parser",
         "Type": "CanvasPathGeometryPage",

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/MarkdownParser/MarkdownParserPage.xaml

@@ -63,6 +63,7 @@ private void RenderMarkdown()
                 try
                 {
                     // Try to parse the markdown.
+#pragma warning disable CS0618 // Type or member is obsolete
                     MarkdownDocument markdown = new MarkdownDocument();
                     foreach (string str in SchemeList.Split(',').ToList())
                     {
@@ -71,6 +72,7 @@ private void RenderMarkdown()
                             MarkdownDocument.KnownSchemes.Add(str);
                         }
                     }
+#pragma warning restore CS0618 // Type or member is obsolete
 
                     markdown.Parse(Text);
 

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/MarkdownParser/MarkdownParserPage.xaml.cs

@@ -17,24 +17,8 @@
     <None Include="$(OutDir)\Design\$(MSBuildProjectName).Design*.dll;$(OutDir)\Design\$(MSBuildProjectName).Design*.pdb" Pack="true" PackagePath="lib\$(TargetFramework)\Design" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Compile Update="Properties\Resources.Designer.cs">
-      <DesignTime>True</DesignTime>
-      <AutoGen>True</AutoGen>
-      <DependentUpon>Resources.resx</DependentUpon>
-    </Compile>
-  </ItemGroup>
-
-  <ItemGroup>
-    <EmbeddedResource Update="Properties\Resources.resx">
-      <Generator>ResXFileCodeGenerator</Generator>
-      <LastGenOutput>Resources.Designer.cs</LastGenOutput>
-    </EmbeddedResource>
-  </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="ColorCode.UWP" Version="2.0.6" />
-    <ProjectReference Include="..\Microsoft.Toolkit.Parsers\Microsoft.Toolkit.Parsers.csproj" />
     <ProjectReference Include="..\Microsoft.Toolkit.Uwp.UI.Controls.Core\Microsoft.Toolkit.Uwp.UI.Controls.Core.csproj" />
     <ProjectReference Include="..\Microsoft.Toolkit.Uwp.UI\Microsoft.Toolkit.Uwp.UI.csproj" />
   </ItemGroup>

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/samples.json

@@ -0,0 +1,11 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Toolkit.Parsers
+{
+    internal static class Constants
+    {
+        internal const string ParserObsoleteMsg = "Parsing code has been deprecated, we suggest using Markdig. See https://github.com/windows-toolkit/WindowsCommunityToolkit/issues/3200 for more info.";
+    }
+}

Microsoft.Toolkit.Uwp.UI.Controls.Markdown/MarkdownTextBlock/MarkdownTextBlock.Methods.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
 using System.Collections.Generic;
 
 namespace Microsoft.Toolkit.Parsers
@@ -10,6 +11,7 @@ namespace Microsoft.Toolkit.Parsers
     /// Parser interface.
     /// </summary>
     /// <typeparam name="T">Type to parse into.</typeparam>
+    [Obsolete(Constants.ParserObsoleteMsg)]
     public interface IParser<out T>
         where T : SchemaBase
     {