Changed some project settings

src/SutForge/SutForge.csproj

@@ -1,23 +1,30 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net8.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <RootNamespace>Sutb</RootNamespace>
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
         <Title>SUT Forge</Title>
         <Authors>dovic95</Authors>
+        <PackageTags>TDD unit-testing chicago classical SUT testing</PackageTags>
         <Description>Simplifying .NET unit testing and Test-Driven Development with an intuitive builder pattern, classical approach, and high extensibility for effortless creation and customization of System Under Test instances.</Description>
         <PackageProjectUrl>https://github.com/dovic95/SUTForge</PackageProjectUrl>
         <PackageLicenseUrl>https://github.com/dovic95/SUTForge/blob/main/LICENSE</PackageLicenseUrl>
         <RepositoryUrl>https://github.com/dovic95/SUTForge</RepositoryUrl>
         <PackageTags>dotnet tdd tests chicago classical</PackageTags>
+        <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
     </PropertyGroup>
 
+    <!-- Disable nullability warnings on older frameworks because there is no nullability info for BCL -->
+    <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+        <Nullable>annotations</Nullable>
+    </PropertyGroup>
+
     <ItemGroup>
-      <PackageReference Include="Microsoft.Extensions.Configuration" Version="8.0.0" />
-      <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
+        <PackageReference Include="Microsoft.Extensions.Configuration" Version="8.0.0" />
+        <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
+        <PackageReference Include="PolyShim" Version="1.8.0" PrivateAssets="all" />
     </ItemGroup>
 
 </Project>