The Package is quite messy to share it includes all the Application libraries an executable and then the appSetting configuration.
If you review this thread you can get a build up and running quite quickly based off an empty site
I see now you mean the attachment. we can have updated
In the link https://docs.developers.optimizely.com/digital-experience-platform/v1.2.0-dxp-cloud-services/docs/code-package-format is an example nupgk file that is for CMS 11 (https://world.optimizely.com/globalassets/documentation/alloy.cms.app.1.2.1.nupkg). Is there any example code package file for CMS 12? It would be nice to have it in the documentation.