Support FastAPI Routes Without Explicit Index Specification

[Sn3llius]

Currently, FastAPI routes require explicitly specifying an index. This can be cumbersome and error-prone, especially for larger applications with many routes. It would be beneficial to have a mechanism that allows FastAPI routes to be defined without the need to specify an explicit index, making route definitions cleaner and more intuitive.

Possible Solution:

Implement an internal mechanism in FastAPI that automatically manages route indexing, ensuring routes are registered in the order they are added.