update_history_en.md

# Release Notes

* 2020.07.14
    * Add `Res2Net200_vd_26w_4s_ssld` pretrained model, whose Top-1 Acc on ImageNet1k dataset reaches 85.13%.
    * Add `Fix_ResNet50_vd_ssld_v2` pretrained model, whose Top-1 Acc on ImageNet1k dataset reaches 84.00%.

* 2020.06.17
    * Add English documents。

* 2020.06.12
    * Add support for training and evaluation on Windows or CPU.

* 2020.05.17
    * Add support for mixed precision training.

* 2020.05.09
    * Add user guide about Paddle Serving and Paddle-Lite.
    * Add benchmark about FP16/FP32 on T4 GPU.

* 2020.04.14
    * First commit.