fix: improve middleware register specification for laravel 11 and 12

[PanchoDP]

The commit improves middleware registration documentation for Laravel 11 and 12 by:

1. Clearer guidance: Replaces "No middleware files" statement with specific instructions on where and how to register middlewares
2. Practical information: Explicitly documents that middlewares are now registered declaratively in bootstrap/app.php using Application::configure()->withMiddleware(), not in Kernel.php
3. Reduces migration confusion: Helps developers transitioning from Laravel 10 understand the architectural change in middleware registration
4. Consistency: Applies the same documentation improvements to both Laravel 11 and 12 templates