List tasks from all the files.

[sonu-kumar-saw]

I am using this application to track my daily task.

for example:

todo-cli-app init 05-05-2024
this will have the task for the date 05-05-2024.

Next day, I want to create a new todo list, 06-05-2024.
So, I will create a new file, ```todo-cli-app init 06-05-2024.

Now, if I list the tasks, I want a flag, such that, it can list all the the task (if not removed) from all the files.

This will help me track the task which I have not completed from yesterday.

If you approve this feature, I can create a PR.

[wujackwill]

Sure, why not. Thank you for the contribution. Can't wait to see the PR.