Include tooling files in project

Author: Lamparter

Directory.Build.props

@@ -6,4 +6,9 @@
     <MinimalWindowsVersion>10.0.19041.0</MinimalWindowsVersion>
     <WindowsSdkPackageVersion>10.0.22621.57</WindowsSdkPackageVersion>
   </PropertyGroup>
+  <ItemGroup>
+    <None Include="$(MSBuildThisFileDirectory)\.editorconfig" />
+    <None Include="$(MSBuildThisFileDirectory)\Directory.Build.props" />
+    <None Include="$(MSBuildThisFileDirectory)\Directory.Packages.props" />
+  </ItemGroup>
 </Project>