Added the rate limit middleware.

README.md

@@ -86,6 +86,17 @@ repeat {
 } while cursor != nil
 ```
 
+### Handling Rate Limits
+
+Add `RateLimitMiddleware` before the authentication middleware to retry `429 Too Many Requests` responses:
+
+```swift
+middlewares: [
+    RateLimitMiddleware(),
+    BearerAuthMiddleware { try await tokenProvider.token() }
+]
+```
+
 ## Supported Platforms
 
 - iOS 14.0+