docs: Add example of using AsyncLocalStorage to README

[chimame]

Thanks for the great library.
Using this library has made Remix even easier to use.

I realized that I could use AsyncLocalStorage, so I added an example of how to use it to the README.

If you don't mind the usage method, why not add it?

[yusukebe]

Hi @chimame

Looks good! But have you ever tried the Context Storage Middleware? I've never tried it, but it will work. If so, this middleware will be suitable for this use-case instead of using AsyncLocalStorage from scratch.

https://hono.dev/docs/middleware/builtin/context-storage

[chimame]

Thank you for checking.

I changed it to a usage example that uses Context Storage Middleware. I confirmed that the code I wrote actually works.

[yusukebe]

I'm just curious. Is it difficult to get a Header object in loader without this way using AsyncLocalStorage?

[chimame]

It's very simple.

export const loader = ({ request }: LoaderFunctionArg) => {
  const cookie = request.headers.get('Cookie')
}

Remix can be retrieved easily like this. Originally, I wanted to write it in the server processing function called from loader rather than in loader, but I was worried that doing so would increase the amount of sample program description in the README.

Shall I write it in an easy-to-understand way?

[yusukebe]

LGTM!

[yusukebe]

Thanks, @chimame !

Looks good. I'll merge this now.