Add pydantic and sphinx-pydantic to serialisation formats, data validation, and future API 

* pydantic
  * [ ] [GitHub](https://github.com/samuelcolvin/pydantic)
  * [ ] [Docs](https://pydantic-docs.helpmanual.io/)
  * [ ] [Fast API Extra Models](https://fastapi.tiangolo.com/tutorial/extra-models/)
* sphinx-pydantic
  * [ ] [GitHub](https://github.com/Zsailer/sphinx-pydantic)
  * [ ] [Docs](https://sphinx-pydantic.readthedocs.io/en/latest/)