Added docker compose setup with 3 node etcd cluster

[subkanthi]

docker compose setup with 3 node etcd cluster.

 insert -p flowers.iris file://iris.parquet
2026-04-27 13:50:50 [-5-thread-1] INFO c.a.i.c.internal.cmd.Insert > file://iris.parquet: processing
2026-04-27 13:50:50 [-5-thread-1] INFO c.a.i.c.internal.cmd.Insert > file://iris.parquet: copying to s3://bucket1/flowers/iris/data/1777315850733-31e515659a185bbdc820b3b19c90384ca5a77530f265cdaa2313b8e0c6f9bd80.parquet
2026-04-27 13:50:51 [-5-thread-1] INFO c.a.i.c.internal.cmd.Insert > file://iris.parquet: adding data file (copy took 0s)
2026-04-27 13:50:51 [main] INFO o.a.i.SnapshotProducer > Committed snapshot 3873137362459299979 (MergeAppend)