rename window/render* to io/window*

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

src/io/window.c

@@ -0,0 +1,23 @@
+// Copyright (c) 2025 Quinn
+// Licensed under the MIT Licence. See LICENSE for details
+#include "window.h"
+
+#include <GLFW/glfw3.h>
+#include <stdlib.h>
+
+// macros for ease of access
+#define WIN_NAME           "MCA Selector Lite"
+#define WIN_DEFAULT_WIDTH  640
+#define WIN_DEFAULT_HEIGHT 480
+
+int window_init(struct renderdat* restrict rdat) {
+	GLFWwindow* const win = glfwCreateWindow(WIN_DEFAULT_WIDTH, WIN_DEFAULT_HEIGHT, WIN_NAME, NULL, NULL);
+	if (win == NULL) return 1;
+	rdat->win = win;
+
+	return 0;
+}
+
+void window_free(struct renderdat* restrict rdat) {
+	glfwDestroyWindow(rdat->win);
+}

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);