Add WASI P3 examples

WASI P3 is almost here! We should add some WASI P3 examples. For example, we could add a streamed response example. I am not sure where this would fit in the structure of the component book right now. @itowlson do you have any ideas here? Maybe a tutorial?

首先阅读现有的 component book 结构，以确定 WASI P3 示例应放置在哪里。重点添加流式响应示例等示例，并考虑教程是否是合适的格式；完成的标准是这些示例已包含在一个有文档记录且达成共识的位置中。

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