Added CLI ref

Author: ruhanponnada

api-playground/openapi/setup.mdx

@@ -9,7 +9,7 @@ To describe your endpoints with OpenAPI, make sure you have a valid OpenAPI
 document in either JSON or YAML format that follows the
 [OpenAPI specification](https://swagger.io/specification/). Your document must
 follow OpenAPI specification 3.0+. 
-<Tip>To validate your OpenAPI spec, you can use this command: <br/>`mintlify openapi-check <openapiFilenameOrUrl>`</Tip>
+<Tip>To validate your OpenAPI spec, use our [CLI](https://www.npmjs.com/package/mintlify) and run this command: <br/>`mintlify openapi-check <openapiFilenameOrUrl>`</Tip>
 
 ## Auto-populate API pages