For the functions installing addons, you need to create a folder "extensions" from where you run the django project and place there the XPIs. The Extension needs to have the name of its install.rdf / manifest.json file.
Currently they are:
Things, that will not be included:
- Some cool addons. The addons list should be short and mostly privacy addons.
- Your favourite performance setting. It's not the scope of the project and not all people need the same performance settings.