[airos] added snippet for the undecided about authentication encryption

Author: edoput

docs/source/backends/airos.rst

@@ -259,12 +259,31 @@ And another that set the authentication protocol to WPA2 enterprise, but this is
             {
                 "name": "wlan0",
                 "type": "wireless",
-                "encryption": {
-                    "protocol": "wpa2_enterprise",
-                    "key": "changeme"
+                "wireless": {
+                    "encryption": {
+                        "protocol": "wpa2_enterprise",
+                        "key": "changeme"
+                    }
                 }
             }
         ]
     }
 
+The ``encryption`` property **must** be specified otherwise you will experience a ``ValidationError``, if you are not sure on what you want
+use this snippet to set to no encryption
+
+.. code-block:: json
+
+    {
+        "interfaces": [
+            {
+                "name": "wlan0",
+                "type": "wireless",
+                "wireless": {
+                    "encryption": {
+                        "protocol": "none"
+                     }
+                 }
+            }
+    }
 Leaving the `NetJSON Encryption object <http://netjson.org/rfc.html#rfc.section.5.4.2.1>` empty defaults to no encryption at all.