Cannot find the gradient handler example

[DarrenYing]

📚 The doc issue

We provide a runnable example to demonstrate the use of gradient handler. In this example, we used DataParallelGradientHandler instead of PyTorch DistributedDataParallel for data parallel training.

The example of using customized gradient handler is not found and the url in the doc is 404

[binmakeswell]

Hi @DarrenYing Thank you for your feedback. We will fix it soon. By the way, we are restructuring the documents and examples, and the new version examples will be provided at the following link https://github.com/hpcaitech/ColossalAI/tree/main/examples