Boilerplate generation

One of the trickiest parts of a ComponentizeJS workflow is figuring out the write structure to author the code to.

We should generate the boilerplate outline for the world being targetted as a new `generateBoilerplate` operation, which could become something like `jco componentize-gen world.wit` for example.

I've posted https://github.com/bytecodealliance/jco/issues/152 in jco for the bindgen discussion on this.

先閱讀 issue 以及連結的 jco bindgen 討論，了解提議的 generateBoilerplate 操作及其與 world.wit 輸入的關係。在定義範圍之前，先在 ComponentizeJS 中找到該操作的進入點。完成的標準是該工作流程能夠為指定的 world 產生 boilerplate 大綱。

由索引模型根據 Issue 內容生成。