Add an example class and some demo code to the project.

src/example_class.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "godot_cpp/classes/ref_counted.hpp"
+#include "godot_cpp/classes/wrapped.hpp"
+#include "godot_cpp/variant/variant.hpp"
+
+using namespace godot;
+
+class ExampleClass : public RefCounted {
+	GDCLASS(ExampleClass, RefCounted)
+
+protected:
+	static void _bind_methods();
+
+public:
+	ExampleClass() = default;
+	~ExampleClass() override = default;
+
+	void print_type(const Variant &p_variant) const;
+};