Adds docker compose for full setup

[marshallmcdonnell]

Work includes:

• adding a docker compose with 2 brokers + 1 proxy server + 1 proxy client for testing

[marshallmcdonnell]

The CI is failing on Clippy: https://github.com/INTERSECT-SDK/broker-http-proxy/actions/runs/17333499097/job/49214767764

Yet, only added a docker compose file...

[Lance-Drane]

The CI is failing on Clippy: https://github.com/INTERSECT-SDK/broker-http-proxy/actions/runs/17333499097/job/49214767764

Yet, only added a docker compose file...

this looks like it's because of an update to Clippy, I don't install a specific version in the toolchain because in my experience I generally don't have to deal with very many changes. I fixed Clippy on my feature branch, so don't worry about it.

The compose file looks correct to me, were you able to run the instructions in the README? I generally test using the RabbitMQ UI to send the messages.

I'll go ahead and approve the MR.