docs: updated the Readme doc to include API reference guide (#471)

Author: aaoswal

README.md

@@ -136,6 +136,15 @@ aws.protocols=-restJson1
 
 See [Debugging](docs/debugging.md)
 
+## Getting Help
+
+Use the following sources for information:
+
+* [Check api and developer guides.](https://docs.aws.amazon.com/sdk-for-kotlin/index.html)
+* Check for similar [issues](https://github.com/awslabs/aws-sdk-kotlin/issues) already opened.
+
+If you still can’t find a solution to your problem open an [issue](https://github.com/awslabs/aws-sdk-kotlin/issues/new/choose) or a [discussion](https://github.com/awslabs/aws-sdk-kotlin/discussions/new)
+
 ## Security
 
 Please refer to our [security policy](https://github.com/awslabs/aws-sdk-kotlin/security/policy).