add: Selectable Tile Map Layer/Mouse Controlled Camera

src/Extensions/LinqExtensions.cs

@@ -0,0 +1,12 @@
+using Godot;
+
+namespace Polonium.Extensions;
+
+public static class LinqExtensions
+{
+    public static T RandomSelect<T>(this IEnumerable<T> source)
+    {
+        T[] s = source.ToArray();
+        return s[GD.Randi() % s.Length]; 
+    }
+}