add change log(fix #23)

CHANGELOG.md

@@ -0,0 +1,20 @@
+# Changelog
+Unreleased
+
+## [3.0.0] - 2023-11-08
+### Added
+- Defined data types including:
+  - basic types like `ChainId`,`Nonce`, `AccountId`, `SubAccoundId`, `TokenId` and so on;
+  - transaction types:`ChangePubkey`, `Deposit`, `Withdraw`, `ForcedExit`, `FullExit`, `OrderMatching`, `Transfer`;
+  - contract transaction types: `AutoDeleveraging`, `ContractMatching`, `Funding`, `Liquidation`;
+  - the builder to build the transaction types;
+  - json rpc request and response types;
+  - other types associated with signing, like private key, public key, address, signature and hash.
+- Implement bytes encoding for the all transaction types.
+- Implement zklink signing and Ethereum signing.
+- Support `wasm` and `Golang` bindings for the all above features.
+- Implement Ethereum json rpc signer to interact with the wallet like MetaMask for `wasm` binding.
+- Implement the provider and rpc client to connect the zklink server and Implement the `wasm` binding.
+- Add Rust and Golang unit tests, add wasm tests
+- Add example code in folder `examples`
+- Add Makefile to build the bindings and lint the code.