[Feature]: Support @[code](../foo.js) for code blocks

[buyfakett]

What problem does this feature solve?

在markdown中增加渲染@code
这个功能可以把一些代码和脚本分开存放，可以让markdown更清爽

What does the proposed API look like?

https://v2.vuepress.vuejs.org/zh/guide/markdown.html#%E5%AF%BC%E5%85%A5%E4%BB%A3%E7%A0%81%E5%9D%97

[SoonIter]

it is not the standard of markdown standard such as common-mark, so this syntax should be customized by users via remarkPlugin

这个功能可以把一些代码和脚本分开存放，可以让markdown更清爽
This feature can separate some codes and scripts for storage, making markdown cleaner.

I'm implementing the @rspress/plugin-llms. Separating code and scripts for storage can result in some information loss that cannot be understood by llm. This is not clearer; instead, it makes markdown more difficult to understand. 🤔