Documentation around how to use the Docker image needs to be improved

[davidkel]

The documentation here shows an example using caliper benchmarks but it won't work. There is a note to say it won't work and why which would apply to networks/ethereum/1node-clique/networkconfig.json in caliper-benchmarks for example but doesn't apply to the fabric network shown in the example. The example will of course still fail but now for different reasons.

Now we could change the note and also be more explicit to say it is caliper benchmarks but people are still likely to hit problems especially if they are new to containers.