The explanation on how asynchronous javascript works should be more in-depth

Asynchronous javascript and the event loop are probably some of the most important topics to learn when delving into the more complex aspects of javascript. However, for some reason, 90% of tutorials and such that you can find online are extremely shallow about this topic, if not completely misleading. I don't think this one is misleading, but it's definitely shallow, which is a pity considering that about 90% of javascript.info is great and super in-depth. I think you should explain more thoroughly and with more visual exaples how the runtime environment works (the engine, the web APIs, macro-task and micro-task queue), how calls to web APIs use separate threads (preferably with examples, like what happens in the event loop and runtime environment when i use fetch?), how exactly async/await works (the function's execution is synchronous until the first await, and then it basically acts as if the remaining code in the function exists in a .then callback) and so on. I feel like if someone can do it, it's you guys, i have faith in you.

首先定位关于异步 JavaScript 和事件循环的教程部分；issue 中没有指定文件或测试。查看现有说明，然后规划使用可视化示例更深入地讲解运行时环境、队列、Web APIs、fetch 和 async/await。完成的标准是该部分全面解释所要求的主题，不再停留于浅层内容。