The module is inherited from ModuleBase. So base parameters can be found there.
The main purpose of this module is to emulate a 'package' that the game normally uses to load assets for various purposes (such as levels). Everything in PackageManager should support your 'added' package, except the PackageManager:package function.
Imagine PackageModule module as a delayed AddFilesModule. Instead of loading it right away it will load when you need it.
The name of the module you use as the meta of the module definition is 'Package' or 'PackageModule' if _force_search is set to true in the module definition.
<Package id directory>
The id/path of the package which is used when it is being called to be loaded, unloaded etc
string directory/path relative to the mods directory which contains all files to be added