Update README.md

Author: tugstugi

README.md

@@ -18,7 +18,7 @@ The final private LB score 0.892 was achieved by post processing on the model's
 * single [UNet](https://arxiv.org/abs/1505.04597) model with a [Squeeze-and-Excitation network](https://arxiv.org/abs/1709.01507) encoder
 * no ensembling, no pseudo labeling
 * [object context](https://arxiv.org/abs/1809.00916) in the decoders and in the base
-* symmetric extension of the [Lovasz hinge loss](https://arxiv.org/abs/1705.08790) function (+0.02 private LB):
+* symmetric extension of the [Lovasz hinge loss](https://arxiv.org/abs/1705.08790) function (+0.02 private LB improvement):
 ```python
 def symmetric_lovasz(outputs, targets):
     return (lovasz_hinge(outputs, targets) + lovasz_hinge(-outputs, 1 - targets)) / 2