In order to enable and work with this version of VN2 from the launcher:
- Unpack the contents of Voltaires-Dream-master folder from this zip which you downloaded from GitHub into Documents/Paradox Interactive/Europa Universalis IV/mod
- Run EU4, you should see "Voltaire's Nightmare" mod in the launcher. Add it to a new playset.
- Enable the playset on the first page of the launcher.
- ??
- Profit!