feat(repo): add legacy header files to maintain compatibility

Author: Lzw655

src/ESP_IOExpander.h

@@ -0,0 +1,16 @@
+
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * This file is just to keep the compatibility with the old version of the library. Please use the file `chip/esp_expander_base.hpp` instead.
+ */
+
+#pragma once
+
+#warning "This file is deprecated. Please use the file `chip/esp_expander_base.hpp` instead."
+
+#include "chip/esp_expander_base.hpp"

src/base/esp_io_expander.h

@@ -0,0 +1,16 @@
+
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * This file is just to keep the compatibility with the old version of the library. Please use the file `port/esp_io_expander.h` instead.
+ */
+
+#pragma once
+
+#warning "This file is deprecated. Please use the file `port/esp_io_expander.h` instead."
+
+#include "port/esp_io_expander.h"