I found a simple solution to this.
Firstly, you can create a folder anywhere in your solution, you do not have to stick to the conventions like ‘app_data’ from .net 4.x.
In my scenario, I created a folder called ‘data’ at the root of my project, I put my txt file in there and used this code to read the contents to a string array
var owners = System.IO.File.ReadAllLines(@"..\data\Owners.txt");