adding a link to the new workbook TAS OTel for Spring Boot Application

pages/doc/integrations_custom_app_metrics_howto.md

@@ -55,6 +55,8 @@ Spring Boot is commonly used to build apps running on TAS.
 
 Spring Boot Actuator supports both push and pull models, with the only difference typically being configuration changes. In that case, it becomes relatively easy to switch from push to pull or vice-versa.
 
+See also the VMware Tanzu solutions workbook [Instrumenting TAS OpenTelemetry for Spring Boot Application](https://docs.vmware.com/en/VMware-Tanzu-Reference-Architecture/services/tanzu-solutions-workbooks/solution-workbooks-TAS-OpenTelemetry-SpringBoot-TO.html).
+
 ### Wavefront Proxy Load
 
 All additional custom app metrics increase the load on the Wavefront proxy. You might have to increase the count of Wavefront proxies and to deploy an IaaS load balancer to balance traffic across proxy instances.