Bump MdXaml from 1.21.0 to 1.27.0

Bumps [MdXaml](https://github.com/whistyun/MdXaml) from 1.21.0 to 1.27.0.
- [Release notes](https://github.com/whistyun/MdXaml/releases)
- [Commits](whistyun/MdXaml@v1.21.0...v1.27.0)

---
updated-dependencies:
- dependency-name: MdXaml
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Shadowsocks.WPF/Shadowsocks.WPF.csproj

@@ -50,7 +50,7 @@
 
   <ItemGroup>
     <PackageReference Include="MaterialDesignThemes" Version="4.9.0" />
-    <PackageReference Include="MdXaml" Version="1.21.0" />
+    <PackageReference Include="MdXaml" Version="1.27.0" />
     <PackageReference Include="OxyPlot.Wpf" Version="2.2.0" />
     <PackageReference Include="ReactiveUI.Events.WPF" Version="15.1.1" />
     <PackageReference Include="ReactiveUI.Fody" Version="19.5.41" />