doc: Describe EnableIPv6 setting

src/iwd.config.rst

@@ -74,6 +74,14 @@ The group ``[General]`` contains general settings.
        ``[Network]`` settings for additional settings related to network
        configuration.
 
+   * - EnableIPv6
+     - Values: true, **false**
+
+       Sets the global default that tells **iwd** whether it should configure
+       IPv6 addresses and routes (either provided via static settings,
+       Router Advertisements or DHCPv6 protocol).  This setting is disabled
+       by default.  This setting can also be overriden on a per-network basis.
+
    * - APRanges
      - Values: <IP in prefix notation>