add missing sub-topics

Signed-off-by: Andrew Jandacek <[email protected]>

docs/user-guide/api-mediation/configuration-customizing-management-of-apiml-load-limits.md

@@ -8,6 +8,10 @@ As a system programmer, you can customize your configuration for how API ML mana
  * To change the number of concurrent connections per route passing through the API Gateway, see [Customizing connection limits](./configuration-connection-limits.md).
 
  * To change the global Gateway timeout value for the API ML instance, see [Customizing Gateway timeouts](./configuration-gateway-timeouts.md).
+
+ * To change the number of concurrent requests an application should support and its impact on the size of the Java memory heap, see [Customizing Java Heap sizes](./configuration-customizing-java-heap-sizes.md).
+
+ * To customize the rate limit for each service, see [Customizing Gateway rate limiter](./customizing-gateway-rate-limiter.md).
 
  * Also see the following properties in API Gateway configuration parameters: 
     * `server.maxTotalConnections`