added link

Author: gitName

includes/api-management-custom-metrics-limits.md

@@ -15,4 +15,6 @@ These limits have the following implications for configuring custom metrics in a
 
 * The number of active time series generated by the policy within a 12 hour period is the product of the number of unique values of each configured dimension during the period. For example, if three custom dimensions were configured in the policy, and each dimension had 10 possible values within the period, the policy would contribute 1,000 (10 x 10 x 10) active time series.
 
-* If you configure the policy in multiple API Management instances that are in the same region in a subscription, all instances can contribute to the regional active time series limit.
+* If you configure the policy in multiple API Management instances that are in the same region in a subscription, all instances can contribute to the regional active time series limit.
+
+Learn more about [design limits and considerations ](/azure/azure-monitor/essentials/metrics-custom-overview#design-limits-and-considerations) for custom metrics in Azure Monitor.