readme: Need to work with OpenDelta
  ```
  from transformers import AutoModelForSeq2SeqLM
  t5 = AutoModelForSeq2SeqLM.from_pretrained("t5-base")
  from opendelta import AutoDeltaModel
  delta = AutoDeltaModel.from_finetuned("DeltaHub/lora_t5-base_mrpc", backbone_model=t5)
  delta.log()
  ```
  