Suggestion - geth service name

[yorickdowne]

To make it easier to replace Geth with a minority client, renaming the geth service to something like execution would be helpful.

You could then have a COMPOSE_FILE that combines diva, validator client, beacon/consensus client and execution client as desired, while using the same DNS / service names no matter the underlying client being used.

[yorickdowne]

On further thought -- this feels a little optional. Users can always connect to an existing stack, and how Diva names things is largely irrelevant as long as its internally consistent.