Added the rate limit middleware.

Sources/ASConnectService/Catalogs/ASConnectService.docc/Library.md

@@ -63,6 +63,17 @@ 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() }
+]
+```
+
 ## Topics
 
 ### API Client
@@ -75,6 +86,10 @@ repeat {
 - ``BearerAuthMiddleware``
 - ``APIKeyTokenProvider``
 
+### Rate Limiting
+
+- ``RateLimitMiddleware``
+
 ### Generated Types
 
 - ``Components``