fix PluginLinks undefined in language zh-cn (#3070)

Author: lerte

src/content/docs/zh-cn/plugin/localhost.mdx

@@ -1,6 +1,7 @@
 ---
 title: Localhost
 description: 在生产环境中使用 localhost 服务器。
+plugin: localhost
 ---
 
 import PluginLinks from '@components/PluginLinks.astro';