This repository is no longer maintained. There is an AMAZING community solution to this issue that not only solves the schema merging issue, but also the VSCode intellisense implications of splitting your schema 🚀
🔗 Head over to https://github.com/ajmnz/prisma-import to check it out.
P.S.: Shoutout to Arnau Jiménez for creating this awesome tool!