Try to integrate a test Material with a HLSL shader resource

It didn't work, hence veldrid/veldrid-spirv#2

Author: chances

Game/Content/Shaders.cs

@@ -0,0 +1,8 @@
+namespace Game.Content
+{
+    // TODO: Generate these constants via build script
+    public static class Shaders
+    {
+        public const string Flat = "flat.hlsl";
+    }
+}

Game/Game.cs

@@ -6,6 +6,7 @@
 using Engine.Assets;
 using Engine.Components;
 using Engine.Entities;
+using Game.Content;
 using Veldrid;
 using Veldrid.OpenGL;
 using Veldrid.Sdl2;
@@ -58,6 +59,7 @@ protected override void Initialize()
             AssetDirectoryPaths.Add(AssetType.Shader, "Game.Content.Shaders");
 
             World.Add(EntityFactory.Create<Camera>());
+            World.Add(EntityFactory.Create(new Material("TestMaterial", Shaders.Flat)));
 
             _commandList = ResourceFactory.CreateCommandList();
         }