Update these two docs to make them compatible with the testnet version of CKB and SDK - [ ] [How to Write Contracts](https://github.com/nervosnetwork/ckb-demo-ruby/blob/develop/docs/how-to-write-contracts.md) - [ ] [Usage of SDK](https://github.com/nervosnetwork/ckb-demo-ruby/blob/develop/README.md)
Update these two docs to make them compatible with the testnet version of CKB and SDK