Added tons of opcode documentation, changed license to ISC and a lot of file refactoring.

src/vm/arrays/index_get.c

@@ -1,3 +1,38 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://hanez.org/project/fun/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the ISC license.
+ * https://opensource.org/license/isc-license-txt
+ */
+
+/**
+* @file index_get.c
+ * @brief Implements the OP_INDEX_GET opcode for array and map indexing in the VM.
+ *
+ * This file handles the OP_INDEX_GET instruction, which retrieves an element from
+ * an array or a value from a map using an index or key.
+ *
+ * Behavior:
+ * - Pops the index/key and container from the stack.
+ * - For arrays, retrieves the element at the specified index.
+ * - For maps, retrieves the value associated with the specified key.
+ * - Pushes the retrieved value onto the stack.
+ *
+ * Error Handling:
+ * - Exits with an error if the container is not an array or map, if the index/key
+ *   is of the wrong type, or if the index is out of bounds.
+ *
+ * Example:
+ * // Bytecode: OP_INDEX_GET
+ * // Stack before: [1, [10, 20, 30]]
+ * // Stack after: [20]
+ *
+ * @author Johannes Findeisen
+ * @date 2025-10-16
+ */
+
 case OP_INDEX_GET: {
     Value idx = pop_value(vm);
     Value container = pop_value(vm);