hyperparameter evolution update (#566)

README.md

@@ -51,6 +51,7 @@ $ pip install -U -r requirements.txt
 * [Test-Time Augmentation (TTA)](https://github.com/ultralytics/yolov5/issues/303)
 * [Model Ensembling](https://github.com/ultralytics/yolov5/issues/318)
 * [Model Pruning/Sparsity](https://github.com/ultralytics/yolov5/issues/304)
+* [Hyperparameter Evolution](https://github.com/ultralytics/yolov5/issues/607)
 
 
 ## Environments