Update README.md

Author: iLampard

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@@ -109,6 +109,7 @@ Explore the following tutorials that can be opened directly in Google Colab:
 
 - [![Open in Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/ant-research/EasyTemporalPointProcess/blob/main/notebooks/easytpp_1_dataset.ipynb) Tutorial 1: Dataset in EasyTPP.
 - [![Open in Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/ant-research/EasyTemporalPointProcess/blob/main/notebooks/easytpp_2_tfb_wb.ipynb) Tutorial 2: Tensorboard in EasyTPP.
+- - [![Open in Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/ant-research/EasyTemporalPointProcess/blob/main/notebooks/easytpp_3_train_eval.ipynb) Tutorial 3: Training and Evaluation of TPPs.
 
 ### End-to-end Example