Show timeline ordered by checked date

**Is your feature request related to a problem? Please describe.**
The timeline view only display tasks ordered by the date they were created and there is no way of listing my the date they were checked/done.

**Describe the solution you'd like**
It would be nice to be able to pass a flag (or something) that would group tasks by the date they were closed.

**Additional context**
[nothing]

Start by locating the CLI's timeline view and the current ordering by creation date. Trace how checked or closed dates are represented and how timeline options are parsed; done means an option can group tasks by their checked date, with tests covering the resulting order.

Written by the indexing model from the issue text.