adding missing network field to cron_jobs config description

Author: Naor Livne

docs/config/cron_jobs.md

@@ -14,3 +14,4 @@ The following table shows the config variables used to set individual cron_jobs
 | devices            | list                     | []                                            | []                       | what devices to grant the containers access ,follows docker run --device of host_path:container_path:ro/rwm, use [] for non  |
 | privileged         | bool                     | false                                         | false                    | true - cron gets privileged permissions, false - no privileged permissions                                                   |
 | schedule           | string                   | 0 * * * *                                     | none - must be declared  | the schedule of the cron to run, follows standard linux cron schedule syntax                                                 |
+| networks           | list                     | ["my_network"]                                | ["nebula", "bridge"]     | the networks containers will be part of, if you wish to use "host" or "none" networks make sure that they are alone in the list (["host"] or ["none"]), a default bridge user network named "nebula" is also added in any case which is not "host" or "none", the "nebula" network can either be added explicitly (["nebula", "example-net"]) or implicitly (["example-net"]) and will also be added if an empty list is set ([]), note that aside from the default "nebula" network (& Docker default networks of "bridge", "none", "host") you will have to create what networks you wish to use manually on the worker prior to using them, the main advantage of the default "nebula" user network over the "bridge" network is that it allows container name based discovery so if you have a server with 2 containers named "con1" and "con2" you can ping from "con1" to "con2" just by using "ping con2" from inside "con1"  |