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.

先阅读 issue 以及链接的 jco bindgen 讨论，了解提议的 generateBoilerplate 操作及其与 world.wit 输入的关系。在确定范围之前，先在 ComponentizeJS 中找到该操作的入口点。完成的标准是该工作流能够为指定的 world 生成 boilerplate 纲要。

由索引模型根据 Issue 内容生成。