0.2.0: line threshold is now configurable

This second release (still in beta) of sopel-help brings a new feature: the number of lines of help message that can be sent to a channel is now configurable. By default, it's still 3.

The best way to configure the plugin is to use the official cli tool:

sopel-plugins configure help

Don't forget to use the -c option if needed.

This new feature has automated tests to ensure everything work as intended.

Compatible with Python 3.5+ and Sopel 7+ only.