修改README，增加训练脚本，完善模型转换代码

PyTorch/NLP/BERT/convert_tf_checkpoint.py → PyTorch/NLP/BERT/tf_to_torch/convert_tf_checkpoint.py

@@ -14,9 +14,7 @@
 import torch
 import argparse
 
-#from modeling import BertForPreTraining, BertConfig
-
-from model import BertForPreTraining, BertConfig
+from modeling import BertForPreTraining, BertConfig
 
 def parse_arguments():
     parser = argparse.ArgumentParser()

PyTorch/NLP/BERT/tf_to_torch/layers/__init__.py

+import torch
+
+from .fused_gelu import bias_gelu_impl
+
+__all__ = ["bias_gelu_impl"]