docs: add docs and example for mesh_vlan site parameter

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

docs/site-example/site.conf

@@ -51,6 +51,9 @@
 
     -- Bitrate used for multicast/broadcast packets.
     mesh_mcast_rate = 12000,
+
+    -- (optional) mesh VLAN on 802.11 ad-hoc interface (1-4095)
+    -- mesh_vlan = 14,
   },
 
   -- Wireless configuration for 5 GHz interfaces.
@@ -63,6 +66,7 @@
     mesh_ssid = 'XX:XX:XX:XX:XX:XX',
     mesh_bssid = 'XX:XX:XX:XX:XX:XX',
     mesh_mcast_rate = 12000,
+    -- mesh_vlan = 14,
   },
 
   -- The next node feature allows clients to always reach the node it is

docs/user/site.rst

@@ -66,6 +66,8 @@ wifi24
     of ``ssid`` of your client network, the ``channel`` your community is using,
     ``htmode``, the adhoc ssid ``mesh_ssid`` used between devices, the adhoc
     bssid ``mesh_bssid`` and the adhoc multicast rate ``mesh_mcast_rate``.
+    Optionally ``mesh_vlan`` can be used to setup VLAN on top of the 802.11
+    ad-hoc interface.
     Combined in an dictionary, e.g.:
     ::