Loads files with Build Action set to EmbeddedResource.

EmbeddedResource.cs

using System.IO;
using System.Reflection;

namespace Core.Utils
{
    public static class EmbeddedResource
    {
        public static string ReadString(Assembly assembly, string @namespace ,string filename)
        {
            var stream = assembly.GetManifestResourceStream($"{@namespace}.{filename}");

            var data = string.Empty;

            using (var reader = new StreamReader(stream))
                data = reader.ReadToEnd();

            return data;
        }
    }
}