React-Router config and folder icons

### Type

- [x] File icon
- [x] Folder icon

### Context and associations

`.react-router/`, `react-router.config.ts`

### References

![Image](https://github.com/user-attachments/assets/f88ff534-7abe-49f7-a62e-8d4dfb43ed30)

![Image](https://github.com/user-attachments/assets/72ed2d2b-d622-4b5f-b7e9-7a6e3a3458f9)