support network option

i propose a new field , **networks** that can be used to attach network/s to the running container ie [`docker run -itd --network=my-net busybox`](https://docs.docker.com/engine/reference/commandline/run/#connect-a-container-to-a-network---network)

The issue names no file or test; start by locating the task execution schema definition and reviewing Docker's --network option. Done means the schema represents the proposed networks field for attaching one or more networks to a container, with the project's checks passing.

Written by the indexing model from the issue text.