Merge branch 'feature/add-openthread-docs' into 'master'

docs: add OpenThread docs

See merge request espressif/esp-idf!14488

docs/en/api-reference/index.rst

@@ -14,4 +14,4 @@ API Reference
     Storage <storage/index>
     System <system/index>
     Configuration Options <kconfig>
-    Error Codes Reference <error-codes>
+    Error Codes Reference <error-codes>

docs/en/api-reference/network/esp_openthread.rst

@@ -0,0 +1,32 @@
+Thread
+==========
+
+Introduction
+------------
+
+`Thread <https://www.threadgroup.org>`_ is a IP-based mesh networking protocol. It's based on the 802.15.4 physical and MAC layer.
+
+Application Examples
+--------------------
+
+The :example:`openthread` directory of ESP-IDF examples contains the following applications:
+
+- The OpenThread interactive shell :example:`openthread/ot_cli`.
+- The Thread border router :example:`openthread/ot_cli`.
+
+
+API Reference
+-------------
+
+For manipulating the Thread network, the OpenThread api shall be used.
+The OpenThread api docs can be found at the `OpenThread official website <https://openthread.io/reference>`_.
+
+ESP-IDF provides extra apis for launching and managing the OpenThread stack, binding to network interfaces and border routing features.
+
+.. include-build-file:: inc/esp_openthread.inc
+.. include-build-file:: inc/esp_openthread_types.inc
+.. include-build-file:: inc/esp_openthread_lock.inc
+.. include-build-file:: inc/esp_openthread_netif_glue.inc
+.. include-build-file:: inc/esp_openthread_border_router.inc
+
+

docs/en/api-reference/network/index.rst

@@ -29,6 +29,16 @@ Ethernet
 
 Code examples for the Ethernet API are provided in the :example:`ethernet` directory of ESP-IDF examples.
 
+Thread
+==========
+
+.. toctree::
+   :maxdepth: 1
+
+   Thread <esp_openthread>
+
+Thread is an IPv6-based mesh networking technology for IoT.
+Code examples for the Thread API are provided in the :example:`openthread` directory of ESP-IDF examples.
 
 IP Network Layer
 ================