add training requirements

README.md

@@ -399,6 +399,11 @@ print(f'Onnx-support/Total Models: {len(onnx_list)}/{len(full_list)}')
     Onnx-support/Total Models: 111/126
 
 ## Fine-tune
+### Requirement
+If you want to train this operator, besides dependency in requirements.txt, you need install these dependencies.
+```python
+! python -m pip install datasets evaluate scikit-learn
+```
 ### Get start
 We have prepared some most typical use of [finetune examples](https://github.com/towhee-io/examples/tree/main/fine_tune/6_train_language_modeling_tasks).