Add multi selection in the list view ? #37

Is your feature request related to a problem? Please describe.
Currently, tasks can only be modified one by one.
When dealing with a large number of tasks, this requires too much repetitive work.

Describe the solution you'd like
Add multi-selection support in the list view.

• Press Space on a task to toggle selection on/off
• Highlight the | icon for selected tasks
• Press ESC to exit multi-selection mode
• Allow shortcut keys to apply actions to selected tasks (e.g. z to complete, d to delete, e to edit)
• Execute the action (optionally with a confirmation dialog)

Describe alternatives you've considered

Additional context