rename window/render* to io/window*

this makes more sense, as we'll add more source files in this category

src/io/window.h

@@ -0,0 +1,12 @@
+// Copyright (c) 2025 Quinn
+// Licensed under the MIT Licence. See LICENSE for details
+#pragma once
+
+#include <GLFW/glfw3.h>
+
+struct renderdat {
+	GLFWwindow* win;
+};
+
+int window_init(struct renderdat* restrict rdat);
+void window_free(struct renderdat* restrict rdat);