The {@link AddonManager} scans directories for addon folders and then maintains them in a catalogue. Addons can then
be started which makes them available to the application. When an addon is started it can do the following:
- Any classes the addon has declared are available via the {@link AddonManager::autoload()} method.
- The addon can declare a class ending in "Plugin" and its events will be registered (TODO).
- Any translations the addon has declared will be loaded for the currently enabled locale.