Add comments to clarify skipping provided libraries in mta.yaml

Co-authored-by: Copilot <copilot@github.com>

Author: mofterdinger

mta.yaml

@@ -18,6 +18,8 @@ modules:
       SPRING_PROFILES_ACTIVE: cloud
       JBP_CONFIG_COMPONENTS: "jres: ['com.sap.xs.java.buildpack.jdk.SAPMachineJDK']"
       JBP_CONFIG_SAP_MACHINE_JDK: '{ version: 25.+ }'
+      # Skip provided libraries (e.g. PostgreSQL driver) as they are already included in the Bookshop
+      # See: https://help.sap.com/docs/btp/sap-business-technology-platform/application-provided-library-components?locale=en-US&version=Cloud#jbp_skip_provided_library_components
       JBP_SKIP_PROVIDED_LIBRARY_COMPONENTS: true
     build-parameters:
       builder: custom