Add link to PLUME to examples (#263)

Add PLUME to examples

README.md

@@ -31,6 +31,7 @@ cd halo2-lib
   - [halo2-rsa](https://github.com/zkemail/halo2-rsa/tree/feat/new_bigint)
 - [halo2-fri-gadget](https://github.com/maxgillett/halo2-fri-gadget) -- FRI verifier in halo2.
 - [eth-voice-recovery](https://github.com/SoraSuegami/voice_recovery_circuit) -- Verify the voice recovery process.
+- [PLUME ERC 7524 Signatures](https://github.com/plume-sig/zk-nullifier-sig/pull/83) - Verify deterministic PLUME signatures of Ethereum keys, for private voting nullifiers.
 - [zkEVM signature verification circuit](https://github.com/scroll-tech/zkevm-circuits/tree/develop/zkevm-circuits/src/sig_circuit.rs)
 - [zkEVM tx-circuit](https://github.com/scroll-tech/zkevm-circuits/tree/develop/zkevm-circuits/src/tx_circuit)
 - [webauthn-halo2](https://github.com/zkwebauthn/webauthn-halo2) -- Proving and verifying WebAuthn with halo2.