fix(docs): t_string_async macro example correct implementation

[sabify]

No description provided.

[Baptistemontan]

I know it's a macro but it is still an example, I wanted it to be readable or I would have simply exported it from the library.
Your modifications also lack consistencies, why not also have leptos::prelude::AsyncDerived ?
The $ is indeed missing, but I don't think the , is needed.
And thanks for the typo!

[sabify]

Without catching , ident, it's not possible to pass arguments like t_string_async!(i18n, app_name) and the compiler returns error.

[Baptistemontan]

Without catching , ident, it's not possible to pass arguments like t_string_async!(i18n, app_name) and the compiler returns error.

Ho ok I didn't knew that, thanks !