A configuration object
Optionaloptions: { key?: string }A duration object
The supported formats are:
ms
library.{ days: 2, hours: 6 }.The string forms are naturally only supported if the options.key argument
is passed, since a Config argument always represents an object by its
nature.
This does not support optionality; if you want to support optional durations,
you need to first check the presence of the target with config.has(...) and
then call this function.
Reads a duration from config.