This is an Addon for Godot that allows you to pack a scene into a .pck file. I wrote this for my game but have changed the way I structure mods now, therefore i will leave it here for anyone who might need something similar.
Download the folder and drop it into your Godot project under res://addons, then enable the addon in your project settings. This should open a new dock that allows you to specify data for the packer.
- All data that should be stored in the Mod PCK file needs to be withing the res://mod directory