Merge pull request #57 from privacy-scaling-explorations/update-readme

Add a user guide in the README

README.md

@@ -1,3 +1,20 @@
 # SNARK Verifier
 
 Generic (S)NARK verifier.
+
+## User Guide
+
+This project is tailored for verifying [Halo2](https://github.com/privacy-scaling-explorations/halo2)-generated proofs on Ethereum.
+
+Additionally, within this repository, there is an example provided for verifying an aggregated proof, which serves as proof for multiple other proofs. You can test it by executing `cargo run --example evm-verifier-with-accumulator`.
+
+As this effort is continuously evolving, there are multiple repository variants to choose from. For optimal results:
+
+- Use [Axiom’s fork](https://github.com/axiom-crypto/snark-verifier) of snark-verifier when
+  - You require production-grade quality; Axiom's fork has been audited.
+  - Proof aggregation is necessary.
+- In the future, consider using [halo2-solidity-verifier](https://github.com/privacy-scaling-explorations/halo2-solidity-verifier) for solidity verifier generation. However, please note the following:
+  - The plan is to phase out snark-verifier and shift focus to halo2-solidity-verifier
+  - Keep in mind halo2-solidity-verifier is currently unaudited and has certain limitations, refer to the project README for details.
+  - snark-verifier may encounter issues generating Solidity code due to hitting the contract size limit with large circuits, a problem addressed by halo2-solidity-verifier.
+  - Proof aggregation is not supported in halo2-solidity-verifier at this time.