IO class definition and implementation

[JunCEEE]

Data IO package template:

• https://github.com/PaNOSC-ViNYL/SimEx-Lite/tree/io-class/SimExLite/DiffractionData
• init.py to import DiffractionData.py for the package
• read function to create a DiffractionData instance from a file.
  

  SimEx-Lite/SimExLite/DiffractionData/DiffractionData.py

  Lines 423 to 427 in ae4f7f4

  	def read(filename: str,
  	index=None,
  	format: str = None,
  	**kwargs) -> DiffractionData:
  	"""Read a DiffractionData object from file.

• write function to write a DiffractionData instance into a file.
  

  SimEx-Lite/SimExLite/DiffractionData/DiffractionData.py

  Lines 460 to 462 in ae4f7f4

  	def write(filename: str, object: DiffractionData, format: str,
  	**kwargs) -> None:
  	"""Read a DiffractionData object from file.