Use cl-format to clean up formatted output

Common Lisp's 'format' is the love of my life.
Align task ids when printing task list

I would think there'd be a way to get `cl-format` to consume an
argument to use as the formatted option but if there is one I sure
haven't found it yet.
Clean up cl-format call in print-tasks (arguably)

Ah, there's the format specifier I was looking for. Not sure about
this repeat call though.