No example for Trading Environments

[eramosr16]

• [ ] I have marked all applicable categories:
  • [ ] exception-raising bug
  • [ ] RL algorithm bug
  • [ ] system worker bug
  • [ ] system utils bug
  • [ ] code design/refactor
  • [ x] documentation request
  • [ ] new feature request
• [x ] I have visited the readme and doc
• [x ] I have searched through the issue tracker and pr tracker
• [ x] I have mentioned version numbers, operating system and environment, where applicable:

I went over the examples folder and I see multiple examples of agents learning from the existent environments but there is not example of an agent using this: https://github.com/opendilab/DI-engine/tree/main/dizoo/gym_anytrading

I tried based on current examples and no luck

[Cloud-Pku]

There is a tutorial for gym-anytrading.