Add CONTRIBUTING.md file #648
Description
Description
It would be helpful to include a CONTRIBUTING.md file in this repository.
A contributing guide provides clear instructions for developers who want to contribute, including guidelines on code style, submitting pull requests, reporting issues, and overall workflow. This helps maintain consistency and lowers the barrier for new contributors.
Reference
https://github.com/semaphore-protocol/semaphore/blob/main/CONTRIBUTING.md