openthread: ot extension command refactor

examples/openthread/extension_command/include/esp_ot_cli_extension.h

@@ -0,0 +1,28 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: CC0-1.0
+ *
+ * OpenThread Command Line Example
+ *
+ * This example code is in the Public Domain (or CC0 licensed, at your option.)
+ *
+ * Unless required by applicable law or agreed to in writing, this
+ * software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+#pragma once
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+* @brief Init the custom command.
+*
+*/
+void esp_cli_custom_command_init(void);
+
+#ifdef __cplusplus
+}
+#endif