Paper recommendation for Part 7: Efficient System2

[woominsong]

Thanks for your amazing work! I reached out to introduce a new paper regarding Efficient System 2:
Accelerated Test-Time Scaling with Model-Free Speculative Sampling (https://arxiv.org/abs/2506.04708)

This work explores a model-free speculative decoding strategy that can utilize overlaps in multi-trajectory reasoning. I believe this will be a useful addition to the Efficient System 2 section of the repository!

I have also opened a pull request here - #18