Figure out and document how to use devcontainer with GitHub codespace

I discovered that GitHub codespace also supports devcontainer.

https://github.com/nodejs/node/pull/60472#issuecomment-3467843933

This means for new Node.js contributors, they do not even need to download or install anything locally to start hacking on Node.js. Just click a few buttons on GitHub and they can start working on changes in the browser, and they can run tests in the container from the code space etc. as well. This might be very useful in code and learn sessions.

I don't know what extension codespace supports, but at least debugging the JS part of Node.js should be possible if the ports are set up correctly. One can always do command line debugging in the terminal in the code space as well. Or good old printing.

Codespace seems to be a paid feature but there's free tier available (?) so we'd be careful about directing people to it though

首先查看当前的 devcontainer 设置以及关于 GitHub Codespaces 的相关 Node.js pull-request 讨论。记录在 Codespace 中打开项目、运行测试和调试的步骤，同时明确说明可用的扩展以及付费层级或免费层级的任何限制。