add amend doc [skip ci]
modify amend doc
- [Snapshot](system_management/snapshot.md)
- [Batch Tx](system_management/batch_tx.md)
- [Emergency Brake](system_management/emergency_brake.md)
+ - [Amend Data](system_management/amend.md)
- Json-RPC Guide
- [Json-RPC List](rpc_guide/rpc.md)
- [Json-RPC Parameters and Returns](rpc_guide/rpc.md)
