Reorganize host and component code

Now that we're storing code for components and hosts in the repository, we should likely reorganize the code tree of the repository itself.

Some issues:

- We have a python host that should probably be close to the rust host (`example-host` assumes Rust, but we should probably have folders for different langauges)
- Components should be more consistently organized under a scheme like `/`, rather than what we have now (i.e. `python/adder`, `js/adder`, `rust/calculator`, etc)

首先盘点现有的 host 和 component 目录，包括 python/adder、js/adder、rust/calculator 和 example-host。确定并记录一致的语言/教程布局，然后验证 host 和 component 已按此分组，同时不遗漏任何示例。

由索引模型根据 Issue 内容生成。