Update Microsoft.Windows.SDK.Win32Docs to 0.1.12-alpha.

Author: alexrp

Directory.Packages.props

@@ -26,7 +26,7 @@
         <PackageVersion Include="Microsoft.Windows.CsWin32"
                         Version="0.2.164-beta" />
         <PackageVersion Include="Microsoft.Windows.SDK.Win32Docs"
-                        Version="0.1.8-alpha" />
+                        Version="0.1.12-alpha" />
         <PackageVersion Include="Microsoft.Windows.SDK.Win32Metadata"
                         Version="37.0.34-preview" />
         <PackageVersion Include="System.IO.Pipelines"