[l10n] Complete translations (#3794)

**Short description**: I completed the translations with the help of
translation tools.

**Long description**: I'm currently looking at the translation-tests and
I noticed the e2e-test `${language} should contain all base keys, ()`.
It is supposed to check whether all keys are present in each translation
file, but it doesn't actually work that way. When I fix it, a lot of
missing translations are reported. I have completed these translations
with the help of translation tools and packed them into this PR. I have
left out the modified test so that we can focus on the question if we
accept such amount of automatic translations or not.

rejas has already expressed in another PR
(https://github.com/MagicMirrorOrg/MagicMirror/pull/3775#discussion_r2083099252)
that he prefers human translators. I basically do too, but I don't see
how we can manage to have all translations completed by humans. And even
if a few translations are not correct, hopefully a user will get in
touch.

If we decide against the translations, we should at least remove the
test. If we go for the tranlsations, I'll add the test.

What do you think?

---------

Co-authored-by: Magnus <34011212+MagMar94@users.noreply.github.com>

translations/zh-cn.json

@@ -28,9 +28,23 @@
 	"NNW": "北偏西风",
 
 	"FEELS": "体感 {DEGREE}",
+	"PRECIP_POP": "降水概率",
+	"PRECIP_AMOUNT": "降水量",
+
+	"MODULE_CONFIG_CHANGED": "模块{MODULE_NAME}的配置选项已更改。\n请查看文档。",
+	"MODULE_CONFIG_ERROR": "模块{MODULE_NAME}发生错误。{ERROR}",
+	"MODULE_ERROR_MALFORMED_URL": "URL格式错误。",
+	"MODULE_ERROR_NO_CONNECTION": "无网络连接。",
+	"MODULE_ERROR_UNAUTHORIZED": "授权失败。",
+	"MODULE_ERROR_UNSPECIFIED": "请查看日志以获取更多详细信息。",
+
+	"NEWSFEED_NO_ITEMS": "目前没有新闻。",
 
 	"UPDATE_NOTIFICATION": "MagicMirror²有新的版本。",
 	"UPDATE_NOTIFICATION_MODULE": "{MODULE_NAME}模块可更新。",
 	"UPDATE_INFO_SINGLE": "当前已安装版本比{BRANCH_NAME}分支落后{COMMIT_COUNT}次代码更新。",
-	"UPDATE_INFO_MULTIPLE": "当前已安装版本比{BRANCH_NAME}分支落后{COMMIT_COUNT}次代码更新。"
+	"UPDATE_INFO_MULTIPLE": "当前已安装版本比{BRANCH_NAME}分支落后{COMMIT_COUNT}次代码更新。",
+	"UPDATE_NOTIFICATION_DONE": "{MODULE_NAME}模块更新完成。",
+	"UPDATE_NOTIFICATION_ERROR": "{MODULE_NAME}模块更新错误。",
+	"UPDATE_NOTIFICATION_NEED-RESTART": "需要重启MagicMirror。"
 }