Add task comments support

**Is your feature request related to a problem? Please describe.**
I want to see an option in which I could add a comment to a task and keep it all organized.
It would be nice to keep track on tasks that demands more than a few hours to finish.

**Describe the solution you'd like**
It would have something like `tb 1 --add-comment This task's on hold because of that.

**Additional context**
A plus would be if it has a feature to list comments enumerated with some option to edit/sort/remove comments.

No files or tests are named. Start by tracing how the CLI parses `tb 1` and persists task data, then clarify whether listing, editing, sorting, and removing comments are required; done means comments can be added and the agreed operations work with test coverage.

Written by the indexing model from the issue text.