#36 Issue: Add Improved Logic for Task Manager

[Shrasht]

The Task Manager application has been updated with improved logic to handle task management more efficiently. This includes functionality for adding tasks, marking them as completed, and displaying completed tasks along with the date and time they were completed. Additionally, tasks can be toggled back to incomplete status if needed. All actions are fully styled for better visual appearance.

Enhancements Made:

Add Task Logic: The addTask function has been improved to:

Ensure empty tasks are not allowed.
Create task elements that include both text and buttons for completion and deletion.
Completed Task Logic:

Added functionality to display the completion timestamp for each completed task.
Tasks can be marked as complete and will move to the "Completed Tasks" section.
The task's buttons for toggling completion and deletion are retained, even after moving between task lists.
Task Styling:

Added better styling for tasks in both the active and completed lists.
Each completed task shows the date and time it was marked as complete in a readable format.
Differentiated styles between active tasks and completed tasks (using .unchecked and .checked classes).
Next Steps:

Review the logic and styling to ensure it meets the project's needs.
Test the task manager for different edge cases like rapidly toggling tasks between active and completed states.
Consider adding a filter or sorting mechanism to organize tasks by completion date or priority.