nit: fix admin tool log level and comments (#1626)

The previous WARNING log levels seems to work, but WARN
aligns better with standard Quarkus log levels.

Fixes #1612

Author: dimas-b

quarkus/admin/src/main/resources/application.properties

@@ -51,6 +51,7 @@ quarkus.index-dependency.protobuf.group-id=com.google.protobuf
 quarkus.index-dependency.protobuf.artifact-id=protobuf-java
 quarkus.datasource.devservices.image-name=postgres:17-alpine
 
-# ---- Logging Configuration ----
-# Set root logging level to WARNING to suppress INFO logs
-quarkus.log.level=WARNING
+## Logging Configuration
+# Set root logging level to WARN to avoid mostly irrelevant Quarkus log messages.
+# The Admin tool communicates with the user via STDOUT/STDERR
+quarkus.log.level=WARN