Added some module architecture

src/Artemis.Core/Constants.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace Artemis.Core
+{
+    public static class Constants
+    {
+        public static readonly string DataFolder =
+            Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData) + "\\Artemis\\";
+    }
+}