Add README and solution tests to build properties

A new line has been added to the build properties to include the README file in the build if it exists. Additionally, the tests associated with the solution have also been made visible internally. This ensures all relevant files and tests are included during the building process.

Directory.Build.props

@@ -31,8 +31,10 @@
     <ItemGroup>
         <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>
         <None Include="../README.md" Pack="true" PackagePath="\" Condition="!Exists('README.md')"/>
+        <None Include="README.md" Pack="true" PackagePath="\" Condition="Exists('README.md')"/>
         <None Include="../icon.png" Pack="true" PackagePath="\" Condition="!Exists('icon.png')"/>
         <InternalsVisibleTo Include="$(AssemblyName).Tests"/>
+        <InternalsVisibleTo Include="$(SolutionName).Tests"/>
         <InternalsVisibleTo Include="LINQPadQuery"/>
     </ItemGroup>
 </Project>