ci for getting started with dapp-offer-up, docker-compose

[aj-agoric]

This issue is related to Agoric/agoric-sdk#8381 but not the same

From high level, we want two kinds of testing:

1. testing the behavior of init subcommand of packages/agoric-cli in agoric-sdk repo
   1. so that we have test coverage even if the behavior of init subcommand changed in a PR in the future
   2. this is getting-started CI test should actually track Getting Started docs agoric-sdk#8381 and is done
2. testing the behavior of init subcommand of https://www.npmjs.com/package/agoric, i.e. the agoric-cli that's published to npmjs.com
   1. so that the workflow as documented in https://docs.agoric.com/guides/getting-started/ is working for developers reading this doc
   2. this is ci for getting started with dapp-offer-up, docker-compose #48(this issue) and is not yet prioritized

Ref: Agoric/agoric-sdk#8829 (comment)

---

Edit by @LuqiPan

[LuqiPan]

For reference, here's how to do it: Agoric/dapp-agoric-basics#24