How does the file under content/adapters/storage/s3 gets replaced by the directory under /node-modules?

[Artenes]

trafficstars

Question: when this repo gets deployed, the file content/adapters/storage/s3 gets replaced by the directory it points in its content. I would like to know how this is done so I can add a new adapter in the same fashion, so it gets replaced when deployed.

Searched for the whole project and inside some node_modules to see any direct reference to the content/adapters/storage/s3. Also added a new file with another path to see if it got replaced, but nothing happens. Do I need to register these files to be replaced somewhere?