My friend (called Anssus) have translated More planets into Chinese (I've also helped), we can contribute the file for this mod.
MPChinese.zip

Wait I've forgot Advancement
MPChinese.zip
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Hey, Thank you for helping translation. But you can use pull request to make changes to my repo. I'd compare to current zh_cn.lang and your file, it seems got broken on multiple lines. Missing = symbol. etc.

Okay, I'll try to fix it. After that, I'll close this Issue.