Add a summary of transformations supported by aws-sdk-js-codemod (#698)

Author: trivikr

README.md

@@ -45,9 +45,10 @@ $ cat example.ts
 import { DynamoDB } from "@aws-sdk/client-dynamodb";
 const client = new DynamoDB();
 const response = await client.listTables({});
-
 ```
 
+For a summary of supported transformations, check [TRANSFORMATIONS.md](TRANSFORMATIONS.md).
+
 ## License
 
 This library is licensed under the MIT-0 License. See the LICENSE file.