Add new features and improve grade management system clarity

Refactor 'contar_mayores' to return a list and enhance output.

Add option to delete all grades and refactor menu logic

Refactor grade management code for readability and efficiency

Refactor grade verification to improve output clarity

Merge remote-tracking branch 'origin/main'

Update repository URL and directory name in README files

Attached Banner

Attached Banner

Rename files and add detailed README documentation.

Add MIT license to the project

Refactor and enhance qualification validation system

Update menu descriptions for improved clarity

Add menu system for grade management functionality

Add grade validation and management script