Thank you. You are right. You have do it in Construct, too, it's not enough to place the files in windows explorer.
You have to go into Construct, Projects Window, scroll down to the Files folder, right click and import the file. So simple, but easily overlooked.
It works with the JSON already. I struggle to successfully read and print the contents of the .csv, but that might be a .csv-specific problem that I'll surely be able to find a solution to in the csv-plugin thread.