Add zh_CN translation

[hilbert-yaa]

This is a follow-up of #324.

• Add machine translation as a starter version
• Revising the machine translation towards my first draft (overall progress: 25%)
• Tested serving -> LGTM

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[mgeisler]

Hi @hilbert-yaa, thanks a lot for putting up the PR!

Since I don't speak Chinese, I'll find someone who does and ask them to read this 😄

[hilbert-yaa]

Hi @hilbert-yaa, thanks a lot for putting up the PR!

Since I don't speak Chinese, I'll find someone who does and ask them to read this smile

Okay. Note that it's still WIP, and I'll ping you when it's ready for a review. :)

[mgeisler]

Okay. Note that it's still WIP, and I'll ping you when it's ready for a review. :)

Sounds great, thank you very much! I'll put up a language picker in the mean time.

[hilbert-yaa]

We'll be re-working this translation from another starting point, so I'll close this PR for now.