Added minver package

Author: mic-code

SourceGen/SourceGen.csproj

@@ -12,6 +12,10 @@
   </PropertyGroup>
 
   <ItemGroup>
+	  <PackageReference Include="MinVer" Version="6.0.0">
+		  <PrivateAssets>all</PrivateAssets>
+		  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+	  </PackageReference>
     <PackageReference Include="Microsoft.CodeAnalysis.Common" Version="4.14.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.14.0" />
   </ItemGroup>