document per-route rate limiting configuration and examples #105

Summary

Per-route rate limiting is supported but undocumented. The transport-level rateLimit option applies globally, but routes can override with their own limits. The docs don't explain the override mechanism or show examples.

Acceptance Criteria

• Add per-route rate limit examples to the rate limiting guide:
  • Strict limit on login endpoint: rateLimit: {windowMs: 900000, max: 5}
  • Relaxed limit on read endpoint: rateLimit: {windowMs: 60000, max: 1000}
  • Disabled for health check: rateLimit: false
• Explain precedence: route config > router defaults > transport config
• Show interaction with presets (e.g., presets.jsonApi includes a default rate limit)
• Document rateLimit: false to opt out per-route

Related

• ergo rateLimit middleware
• add named presets beyond jsonApi ergo-router#106 (named presets with rate limit defaults)