Including documentation comments in nuget

Source/QuestPDF/QuestPDF.csproj

@@ -22,6 +22,7 @@
         <TargetFrameworks>net462;netstandard2.0;netcoreapp2.0;netcoreapp3.0;net6.0</TargetFrameworks>
         <IncludeSymbols>true</IncludeSymbols>
         <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+        <GenerateDocumentationFile>True</GenerateDocumentationFile>
     </PropertyGroup>
 
     <ItemGroup>