Add Pomodoro style timer to tasks

**Is your feature request related to a problem? Please describe.**
The current functionality allows the user to create, close, adit, delete and mark tasks as done, but it doesn't provide a time tracking feature. It would be nice to add a Pomodoro style timer for added focus.

**Describe the solution you'd like**
Offer another option to start a task with a pomodoro timer. Once the time is up, the console will let the user know that it is done, and if the task should be crossed off, or if they need more time.

**Additional context**
I understand that **taskbook** is meant to be simple and minimalistic, but this feature would be nice to have.

The issue does not name files, tests, or an entry point. Review the task-start flow and existing console interactions first, then define how a Pomodoro timer is started, how completion is reported, and how the user chooses whether to cross off the task or continue.

Written by the indexing model from the issue text.