Addon configuration

[randompersona1]

Addons might require configuration. I see two options:

1. The syncer exposes a configuration directory for addons to read configuration files from
2. The syncer exposes configuration options directly for every addon. Initially, this would presumably be read from a config file, but has the potential to be included into the ui.

While 2 is neater to me, I don't think it's necessary.

[RumovZ]

I don't think there are any changes required to support this. Add-on authors can just store a config.json or similar in their add-on directory and manage it themselves. They can even build a GUI to edit it.

[randompersona1]

That's fair. I was thinking about a folder next to the addon folder that would contain only config files editable by the user, but I didn't even think about hooking into the menu directly.