Update README.md

Author: yinhaofeng

README.md

@@ -118,7 +118,7 @@ python -u tools/static_trainer.py -m models/rank/dnn/config.yaml #  静态图训
   |   召回   |                     [GNN](https://github.com/PaddlePaddle/PaddleRec/tree/release/1.8.5/models/recall/gnn/)                     |    ✓    |    ✓    |     ✓     |     ✓     | [1.8.5](https://github.com/PaddlePaddle/PaddleRec/tree/release/1.8.5) | [AAAI 2019][Session-based Recommendation with Graph Neural Networks](https://arxiv.org/abs/1811.00855)                                                                                                      |
   |   召回   |                     [RALM](https://github.com/PaddlePaddle/PaddleRec/tree/release/1.8.5/models/recall/look-alike_recall/)                     |    ✓    |    ✓    |     ✓     |     ✓     | [1.8.5](https://github.com/PaddlePaddle/PaddleRec/tree/release/1.8.5) | [KDD 2019][Real-time Attention Based Look-alike Model for Recommender System](https://arxiv.org/pdf/1906.05022.pdf)                                                                                                      |
   |   排序   |      [Logistic Regression](models/rank/logistic_regression/)      |    ✓    |    ✓    |     ✓     |     x     | >=2.1.0 | /                                                                                                                                                                                                           |
-  |   排序   |                      [Dnn](models/rank/dnn/)                      |    ✓    |    ✓    |     ✓     |     ✓     | >=2.1.0 | /                                                                                                                                                                                                           |
+  |   排序   |                      [Dnn](models/rank/dnn/)                      |    ✓    |    ✓    |     ✓     |     ✓     | >=2.1.0  | /                                                                                                                                                                                                           |
   |   排序   |                       [FM](models/rank/fm/)                       |    ✓    |    ✓    |     ✓     |     x     | >=2.1.0 | [IEEE Data Mining 2010][Factorization machines](https://analyticsconsultores.com.mx/wp-content/uploads/2019/03/Factorization-Machines-Steffen-Rendle-Osaka-University-2010.pdf)                             |
   |   排序   |                      [FFM](models/rank/ffm/)                      |    ✓    |    ✓    |     ✓     |     x     | >=2.1.0 | [RECSYS 2016][Field-aware Factorization Machines for CTR Prediction](https://dl.acm.org/doi/pdf/10.1145/2959100.2959134)                                                                                    |
   |   排序   |                      [FNN](https://github.com/PaddlePaddle/PaddleRec/tree/release/1.8.5/models/rank/fnn/)                      |    ✓    |    ✓    |     ✓     |     x     | [1.8.5](https://github.com/PaddlePaddle/PaddleRec/tree/release/1.8.5) | [ECIR 2016][Deep Learning over Multi-field Categorical Data](https://arxiv.org/pdf/1601.02376.pdf)                                                                                                          |