Updated Documentation and Improve Error Handling

[ChidinmaIgberaese]

This pull request introduces significant updates to the project, including enhanced documentation and improved error handling. Key changes include:

Updated Documentation:

Added detailed explanations for the LinkedList and QueueWithStacks classes, including their methods and usage.
Provided a comprehensive guide on how to contribute to the project, including branch creation and merging practices.
Enhanced Error Handling:

Improved error handling in the LinkedList class to ensure proper exception handling for empty lists.
Added validation in the QueueWithStacks class to handle empty queue scenarios more gracefully.
Changes:

Updated README.md with new documentation and contribution guidelines.
Refined error messages and handling logic in the LinkedList and QueueWithStacks classes.
Created a new branch documentation/feedback to reflect these changes and ensure they are reviewed separately.