Update how-to-managed-network.md

Added APIM PE support

Author: meerakurup

articles/machine-learning/how-to-managed-network.md

@@ -1077,6 +1077,7 @@ Private endpoints are currently supported for the following Azure services:
 * Azure Database for PostgreSQL
 * Azure Database for MySQL
 * Azure SQL Managed Instance
+* Azure API Management
 
 When you create a private endpoint, you provide the _resource type_ and _subresource_ that the endpoint connects to. Some resources have multiple types and subresources. For more information, see [what is a private endpoint](/azure/private-link/private-endpoint-overview).