create a cn developer site

[yqrashawn]

cn trans can be found here
Great thanks to our community developers.

• create a stand-alone repo for cn, https://github.com/Conflux-Chain/conflux-developer-site-cn
• move the cn docs to each corresponding repo, all PRs can be found at docs: add zh_cn version of docs on developer.conflux-chain.org conflux-doc#21
• move zh-hans docs to Conflux-Chain/zh-hans.developer.conflux-chain.org
• translate home page, Conflux-Chain/zh-hans.developer.confluxnetwork.org@b3aa152
• deploy the zh-hans dev site, https://zh-hans.developer.conflux-chain.org/
• add docs for contributers on how to add new transactions

[yqrashawn]

zh-hans doc is live at https://zh-hans.developer.conflux-chain.org