https://www.statiq.dev/api/statiq.common/configtransformextensions/a54a4f3d
Statiq - TransformTValue, TSource(ConfigTSource, FuncTSource, TValue)
statiqtvalue
https://mongodb.github.io/mongo-csharp-driver/2.13/apidocs/html/P_MongoDB_Driver_BsonDocumentProjectionDefinition_2_Document.htm
BsonDocumentProjectionDefinition(TSource, TProjection).Document Property
documentproperty