记录相关paper的复现

实验基于数据集CLUE-NER，结果如下：

• 验证集结果

  experiment	p	r	f1
  BILSTM-CRF	69.04%	68.19%	68.62%
  TENER	66.10%	64.57%	65.33%
  BERT+CRF	79.16%	81.61%	80.37%
  BERT-pipeline	82.17%	80.86%	81.51%
  BERT-MRC	-	-	-
  Biaffine-NER	84.85%	77.31%	80.90%