Add options toggle to display empty boards / archive boards

**Is your feature request related to a problem? Please describe.**
When you complete all tasks in a board, the board is automatically archived. With my organizational system I prefer seeing empty boards which serve as a reminder that I probably need to determine the next task for that project. Once a project/ board is complete it can then be manually archived. Reviewing past boards from the archive view is not ideal because it contains references to long stale projects. I'm looking to see relevant / current empty projects. My temporary workaround is just to create a task on each board called "active" and never complete it until project is truly ready to be archived.

**Describe the solution you'd like**
Perhaps a config option like displayEmptyBoards? and a way to select a particular board to be archived.

Start by tracing how the CLI archives boards when their tasks are completed and where configuration options and board selection are handled. Done means empty boards can remain visible through an option and individual boards can be manually archived, with the behavior clarified for current and archived boards.

Written by the indexing model from the issue text.