Add licenses, docbook, general cleanup

components/esp32/include/esp_int_wdt.h

@@ -1,6 +1,46 @@
-#ifndef INT_WDT_H
-#define INT_WDT_H
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
 
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef __ESP_INT_WDT_H
+#define __ESP_INT_WDT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @addtogroup Watchdog_APIs
+  * @{
+  */
+
+/**
+  * @brief  Initialize the interrupt watchdog. This is called in the init code, no need to 
+  *         call it explicitly.
+  *
+  * @param  null
+  *
+  * @return null
+  */
 void int_wdt_init();
 
+
+/**
+  * @}
+  */
+
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif