Add Learning What to Defer algorithm for MIS problem example

[Jinyu-W]

Description

Contexts include:

• A simple MIS simulator, which simulates a complete MIS-solving process as a transition;
• Graph-based PPO algorithm implementation, including Policy, TranOps, Trainer, basic networks, and replay memory;
• An EnvSampler and necessary configuration files;
• A README of the brief introduction of this algorithm.

Linked issue(s)/Pull request(s)

• issue_number

Type of Change

• [ ] Non-breaking bug fix
• [ ] Breaking bug fix
• [ ] New feature
• [ ] Test
• [ ] Doc update
• [ ] Docker update

Related Component

• [ ] Simulation toolkit
• [ ] RL toolkit
• [ ] Distributed toolkit

Has Been Tested

• OS:
  • [ ] Windows
  • [ ] Mac OS
  • [ ] Linux
• Python version:
  • [ ] 3.7
  • [ ] 3.8
  • [ ] 3.9
• Key information snapshot(s):

Needs Follow Up Actions

• [ ] New release package
• [ ] New docker image

Checklist

• [ ] Add/update the related comments
• [ ] Add/update the related tests
• [ ] Add/update the related documentations
• [ ] Update the dependent downstream modules usage