CCD to Fhir Mapping

Hi,
Am working on a project that needs to convert CCD to Fhir (stu3) resource. I looked for some packages to do that and found out there is no such package is available for CCD to fhir convertion in nuget for .net core (C#) project.
So i thought of doing it on my own but i cant find a proper documentation to do that. Like which fields of ccd should map to which fields in FHIR (STU3).
can anyone please point me the proper documentation for this CCD to FHIR.

Thanks.

See discussion here: https://chat.fhir.org/#narrow/stream/179191-cda-to.20fhir/topic/CCD.20to.20FHIR.20documentation