refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -4,7 +4,7 @@
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.7" />
+    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.8" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.0.0-1.25259.101" />
     <!-- keep at 17.14.1 -->
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />