added sample in env

Author: AjitPadhi-Microsoft

src/.env.sample

@@ -2,7 +2,8 @@
 AZURE_BASIC_LOGGING_LEVEL=INFO
 # Azure package logging (default: WARNING level to suppress INFO)
 AZURE_PACKAGE_LOGGING_LEVEL=WARNING
-# Comma-separated list of specific logger names to configure (default: empty list uses Azure SDK loggers)
+# Comma-separated list of specific logger names to configure (default: empty - no custom loggers)
+# Example: AZURE_LOGGING_PACKAGES=azure.identity.aio._internal,azure.monitor.opentelemetry.exporter.export._base
 AZURE_LOGGING_PACKAGES=
 
 AZURE_AI_AGENT_API_VERSION=