Pull Request Overview

This PR introduces a new doubly linked list data structure implementation in C++. The implementation provides basic operations for creating nodes, inserting elements, and navigating through the list.

• Adds a complete doubly linked list implementation with node creation and insertion functionality
• Implements navigation functions to move between nodes and traverse to list boundaries
• Includes a demonstration in the main function showing various list operations

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}