Fix text matching document typo (#1186)

Co-authored-by: Zeyu Chen <[email protected]>

Author: wawltor

examples/text_matching/sentence_transformers/README.md

@@ -93,11 +93,11 @@ $ python -m paddle.distributed.launch --gpus "0" train.py --device gpu --save_di
 ```python
 # 使用 ERNIE 预训练模型
 # ernie-1.0
-model = ppnlp.transformers.ErnieModel.from_pretrained('ernie-1.0'))
+model = ppnlp.transformers.ErnieModel.from_pretrained('ernie-1.0')
 tokenizer = ppnlp.transformers.ErnieTokenizer.from_pretrained('ernie-1.0')
 
 # ernie-tiny
-# model = ppnlp.transformers.ErnieModel.from_pretrained('ernie-tiny'))
+# model = ppnlp.transformers.ErnieModel.from_pretrained('ernie-tiny')
 # tokenizer = ppnlp.transformers.ErnieTinyTokenizer.from_pretrained('ernie-tiny')