[Nested routers] Merge/Nest routers easily

[like-engels]

Description of the feature

Hey there! I was wondering if it’d be possible to integrate a more poetic way of nesting/merging routes in Poem. Something that feels intuitive and makes people feel right at home. For example, in web servers like FastAPI, there’s an add_router method that lets you nest routers and makes modularizing the codebase super smooth. I know you can already do this in Poem with .nest("", another_router_object), but honestly, it doesn’t feel very poetic.

So, maybe we could add something like nest_router as an alias or helper method for nest to improve the developer experience? Let me know if I’m missing something here. If this idea is supported, I’d love to open a PR and contribute!. 🚀 🤠

Code example (if possible)

Current approach

/// code somewhere over the rainbow
let v1_router = Route::new().nest("api/v1", {
        Route::new().nest("", another_router_somewhere)
    })
    
 /// main
let app = Route::new().nest("",  v1_router);

Proposed API

/// code somewhere over the rainbow
let v1_router = Route::new().nest("api/v1", {
        Route::new().nest_router(another_router_somewhere)
 })
    
 /// main
let app = Route::new().nest_router(v1_router);

I think we can even streamline the route prefix thing a little bit

/// code somewhere over the rainbow
let v1_router = Route::new().prefix("api/v1")
        .nest_router(another_router_somewhere)
        .nest_router(another_router_somewhere2)
        .nest_router(another_router_somewhere3)
    
 /// main
let app = Route::new().nest_router(v1_router);