Integrate Dioxus Docs Into Docsite

[mcmah309]

A lot of useful information can be found in https://github.com/DioxusLabs/dioxus/tree/main/packages

First at the <package_name>/README level and secondly at <package_name>/docs/*. I would be worth while if this could be integrated into the docsite and made searchable.

Do do so, I propose that https://github.com/DioxusLabs/dioxus/ become a submodule of this repo and a new section crates be added to the docs

Crates
├── ...
├── document
│   ├── head
│   ├── eval
├── ...

This proposal is related to the third bullet here #436

If this proposal and implementation is accepted. I'd be happy to work on it.

[ealmloff]

Some crates like web-sys host their API docs outside of docs.rs. We could do the same for dioxus under a /api-docs route and include the results in the search index. The <package_name>/docs/ folders of the dioxus crates only contain some of the api docs, and they are often not useful on their own. For example, the rules of hooks documentation is added to every hook function's api docs