Add documentation for enable_ipv6 flag. (#1749)

Co-authored-by: Oxan van Leeuwen <oxan@oxanvanleeuwen.nl>

components/ethernet.rst

@@ -150,6 +150,7 @@ Configuration for Wireless Tag WT32-ETH01
 See Also
 --------
 
+- :doc:`network`
 - :apiref:`ethernet/ethernet_component.h`
 - `ESP32 Ethernet PHY connection info <https://pcbartists.com/design/embedded/esp32-ethernet-phy-schematic-design/>`__
 - :ghedit:`Edit`

components/network.rst

@@ -0,0 +1,22 @@
+Network component
+=================
+
+.. seo::
+    :description:
+    :image: network-wifi.svg
+    :keywords: Network, WiFi, WLAN, Ethernet, ESP32
+
+The network component is a global configuration for all types of 
+networks (WiFi, Ethernet).
+
+.. code-block:: yaml
+
+    # Example configuration
+    network:
+        enable_ipv6: true
+        
+Configuration variables:
+------------------------
+
+- **enable_ipv6** (*Optional*, boolean): Enables IPv6 support. Defaults to ``false``. Only available on ESP32 with ESP-IDF framework.
+

components/wifi.rst

@@ -269,5 +269,6 @@ See Also
 --------
 
 - :doc:`captive_portal`
+- :doc:`network`
 - :apiref:`wifi/wifi_component.h`
 - :ghedit:`Edit`

index.rst

@@ -142,6 +142,7 @@ Core Components
     Core, components/esphome, cloud-circle.svg
     WiFi, components/wifi, network-wifi.svg
     MQTT, components/mqtt, mqtt.png
+    Network, components/network, network-wifi.svg
 
     I²C Bus, components/i2c, i2c.svg
     SPI Bus, components/spi, spi.svg