Add environment setup and installation guide

[lqzxt]

Hi PaperScout team, Thanks for sharing this interesting work. The README clearly explains the motivation and framework of PaperScout, but it would be very helpful if the repository could include a more detailed environment setup guide.

Currently, it is not very clear how to prepare the environment and run the code from scratch. Could you consider adding instructions for the following items?

• Required Python version
• Dependency installation steps
• Minimal example commands for running PaperScout

Thanks again for the great work!