docs: dev: add OWE MAC-assignment

Fixes commit 6692095f

docs/dev/mac_addresses.rst

@@ -10,9 +10,9 @@ Gluon tries to solve this issue by using a hash of the primary MAC address as a
 
 * 0: client0; WAN
 * 1: mesh0
-* 2: (unused)
+* 2: owe0
 * 3: wan_radio0 (private WLAN); batman-adv primary address
 * 4: client1; LAN
 * 5: mesh1
-* 6: (unused)
+* 6: owe1
 * 7: wan_radio1 (private WLAN); mesh VPN