Suggestion
Suggestion is a base class that defines the properties which specify how an item will appear and behave in the Fig autocomplete popup.
Every item that appears in the autocomplete popup is backed by a Suggestion object, which defines its icon, name, description and more.
Other types used to construct a completion spec, like Subcommand and Option, are subclasses of Suggestion and inherit its properties. Generators produce a list of Suggestion objects.