Re-introduce prototype code

src/utils/FpsCounter.cs

@@ -0,0 +1,9 @@
+using Godot;
+
+public partial class FpsCounter : Label
+{
+  public override void _Process(double delta)
+  {
+    this.Text = Engine.GetFramesPerSecond().ToString();
+  }
+}

src/utils/GameInputs.cs

@@ -0,0 +1,7 @@
+using Godot;
+
+namespace GameJamDungeon
+{
+  [InputMap]
+  public partial class GameInputs;
+}

src/utils/Instantiator.cs

@@ -0,0 +1,40 @@
+using Godot;
+
+namespace GameJamDungeon
+{
+  /// <summary>
+  /// Utility class that loads and instantiates scenes.
+  /// </summary>
+  public interface IInstantiator
+  {
+    /// <summary>Scene tree.</summary>
+    public SceneTree SceneTree { get; }
+
+    /// <summary>
+    /// Loads and instantiates the given scene.
+    /// </summary>
+    /// <param name="path">Path to the scene.</param>
+    /// <typeparam name="T">Type of the scene's root.</typeparam>
+    /// <returns>Instance of the scene.</returns>
+    T LoadAndInstantiate<T>(string path) where T : Node;
+  }
+
+  /// <summary>
+  /// Utility class that loads and instantiates scenes.
+  /// </summary>
+  public class Instantiator : IInstantiator
+  {
+    public SceneTree SceneTree { get; }
+
+    public Instantiator(SceneTree sceneTree)
+    {
+      SceneTree = sceneTree;
+    }
+
+    public T LoadAndInstantiate<T>(string path) where T : Node
+    {
+      var scene = GD.Load<PackedScene>(path);
+      return scene.Instantiate<T>();
+    }
+  }
+}