Add GitHub Action to find Python syntax errors

Update README.md

Removed query string from the video link - not only is it unnecessary, it also messes with Bilibili's stats tracking.

使用NumPy读取MNIST文件信息

GitHub Actions will need to be enabled at https://github.com/dragen1860/Deep-Learning-with-PyTorch-Tutorials/actions

False

修改由于TensorFlow升级到2.0，导致ch1的tf1.py错误。

由于使用TensorFlow2导致的问题。