Add API Rate Limiting Documentation

## Description
With 35,418+ commits, this project has evolved significantly. As the IAM components grow, clear documentation on API rate limiting would be valuable for developers.

## Suggestion
- Document rate limits for different API endpoints
- Provide examples of handling rate limit responses
- Include best practices for API usage
- Add rate limit headers documentation

## Benefits
- Prevents API abuse
- Helps developers plan their integration
- Improves overall API experience

The issue names no files, tests, or documentation entry points. Start by locating the project's API documentation and the relevant endpoints and rate-limit response headers; done means the documentation covers endpoint limits, response-handling examples, headers, and usage best practices.

Written by the indexing model from the issue text.