Adds CLI-Todo List Application

[GideonBature]

PR Description: Add Rust CLI Todo List Application

This pull request introduces a command-line interface (CLI) application for managing todos, built with Rust. The application provides basic CRUD (Create, Read, Update, Delete) functionality for todo items with persistent storage.

Features:

• Interactive command-line interface with menu-driven navigation
• Todo items with title, description, due date, priority level, and status
• Create new todo items with custom details
• Read/view all stored todo items
• Update existing todo items (any field can be modified)
• Delete unwanted todo items
• Persistent storage using a simple text file format
• Error handling for file operations and user input

Technical Implementation:

• Written in Rust (edition 2024)
• Uses standard library modules for file I/O and data structures
• Simple data persistence via plaintext file with pipe-separated values
• No external dependencies required

Usage:

After building the application, users can:

1. Create todos with title, description, due date, and priority
2. View all stored todos
3. Update todo fields (description, due date, priority, status)
4. Delete todos by title
5. Data is automatically saved on exit