Fix [2] to [3]

Author: yzhan289

datadog_checks_dev/datadog_checks/dev/tooling/templates/integration/check/{check_name}/README.md

@@ -6,7 +6,7 @@ This check monitors [{integration_name}][1] through the Datadog Agent.
 
 ## Setup
 
-Follow the instructions below to install and configure this check for an Agent running on a host. For containerized environments, see the [Autodiscovery Integration Templates][2] for guidance on applying these instructions.
+Follow the instructions below to install and configure this check for an Agent running on a host. For containerized environments, see the [Autodiscovery Integration Templates][3] for guidance on applying these instructions.
 
 ### Installation