docs: add known issues link to MRAP (#2828)

Author: AllanZhengYP

README.md

@@ -42,6 +42,7 @@ visit our [code samples repo](https://github.com/aws-samples/aws-sdk-js-tests).
    1. [Middleware Stack](#middleware-stack)
 1. [Install from Source](#install-from-Source)
 1. [Giving feedback and contributing](#giving-feedback-and-contributing)
+1. [Known Issues](#known-issues)
 
 ## Getting Started
 
@@ -464,3 +465,7 @@ client.middlewareStack.add(middleware, {
 ```
 
 For a full middleware stack deep dive please check out our [blog post](https://aws.amazon.com/blogs/developer/middleware-stack-modular-aws-sdk-js/).
+
+## Known Issues
+
+1. [S3 Multi-Region Access Point(MRAP) is not available unless with additional dependency](https://github.com/aws/aws-sdk-js-v3/issues/2822)