Document what chaincode-functions-v2 means in docker vs k8s generators

Follow-up from #684 — dzikowski explained that the v2 label on those scripts isn’t “Fabric 2 vs 3” in every code path.

I almost filed the same thing as #683 before reading that thread. The confusing bit is that setup-docker picks `chaincode-functions-${v2|v3}.sh` using `isV3` (HLF3 vs HLF2 Fablo profile), while setup-k8s uses `isV2` vs `v1.4` for a completely different reason (old 1.4-style install flow vs newer). Same filename pattern, different meaning — easy to grep wrong.

Could we add a few lines of comment above each `_copyUtilityScripts` copy step in `src/setup-docker/index.ts` and `src/setup-k8s/index.ts`, each pointing at the other so people don’t assume the suffixes line up? CONTRIBUTING blurb optional if that’s too noisy in the source.

Refs: #683 #684