[Documentation] TigerTune: Document supported hyperparameters in README

[tigerlab-ai]

Both textGenerationTransformersFineTuneEngine and textClassificationTransformersFineTuneEngine support a bunch of hyper parameters. They're only documented in the code, but not README:

tiger/TigerTune/tigertune/finetuning/llm/text_classification_transformer.py

Line 21 in 8ad8d38

hyperparameters (`Optional[Dict[str, Union[str, int, float]]]`):

and

tiger/TigerTune/tigertune/finetuning/llm/text_generation_transformer.py

Line 17 in 8ad8d38

hyperparameters (`Optional[Dict[str, Union[str, int, float]]]`):

It will be useful to also document these hyper parameters in TigerTune/README.md