Add verbose mode for the cli

[abunashir]

Based on the recent update in metanorma, we've different levels of logging and we've also changed it to display only the :warning and errors.

But in the long run, it might be useful to add some verbose mode, so the user can decide if they want to see what's going on under the hood, and also to pinpoint any issues during the development.

Related:

• Processors related debugging information #27
• Add configurable log setting for metanorma metanorma#55

[ronaldtse]

Agree. Thanks for the suggestion @abunashir !