introduce starknet warp route & infra config example

[swiiny]

Summary

This PR adds a fully runnable Warp‑route example, complete with documentation, scripts, and infra configs, so teams can stand up a Starknet ↔ Gnosis Chiado route with Hyperlane in just a few commands.

Motivation

Until now the repository offered reference contracts but no end‑to‑end guide for deploying and exercising a Warp route.
Teams interested in re‑using the implementation had to piece the flow together from code and scattered notes, costing time (and brain‑cells).
By contributing a ready‑to‑run example we:

• shorten the on‑ramp for new integrators,

• provide a concrete template they can adapt to their own token,

• keep the main repo as the single source of truth for both code and usage.

What’s included

Area	Highlights
example/ project	Complete TypeScript sample (deployment, bridging) managed via its own package.json.
Deployment guide	Step‑by‑step instructions in example/README.md; linked from the root README.
Env & config templates	.env.example files and infra/config.json for chain‑specific params.
Relayer setup	docker-compose.relayer.yml for spinning up a local Hyperlane relayer.
Scripts	deploy-route.ts to deploy Warp contracts; bridge.ts to lock/mint & burn/unlock test tokens.