Update rc2 encode protocol (FISCO-BCOS#653)

* update protocol description

* update rc2 description

fix error spelling

Merge pull request FISCO-BCOS#483 from HoweChen/patch-1

修改核心流程阶段英文错误

Merge pull request FISCO-BCOS#27 from FISCO-BCOS/dev

fix doc bugs of FISCO-BCOS-DOC

fix all-bugs of web3sdk and sdk