Fix link to Open API Documentation in Redis Data Integration API reference

Author: spicy-sauce

content/integrate/redis-data-integration/reference/api-reference.md

@@ -13,7 +13,7 @@ aliases:
 This is the REST API reference for Redis Data Integration services.
 The API provides endpoints to manage and monitor your Redis Data Integration deployments.
 
-[Open API Documentation](api/index.html)
+[Open API Documentation](./api/index.html)
 
 ## Authentication