Improve the documentation for quarkus.log.file.rotation.file-suffix:

https://docs.redhat.com/en/documentation/red_hat_build_of_quarkus/3.8/html/logging_configuration/logging#loggingConfigurationReference

1) State that the suffix must be in a date-time format that is understood by [java.time.format.DateTimeFormatter](https://github.com/openjdk/jdk/blob/fbe4cc96e223882a18c7ff666fe6f68b3fa2cfe4/src/java.base/share/classes/java/time/format/DateTimeFormatter.java).

See upstream issue:

https://github.com/quarkusio/quarkus/issues/42068

2) Provide more example quarkus.log.file.rotation.file-suffix patterns?

3) I don't think this is relevant and should be removed?
"Note: If the suffix ends with .zip or .gz, the rotation file will also be compressed."

I think that that applies to "quarkus.log.handler.file."file-handlers".rotation.file-suffix" and not "quarkus.log.file.rotation.file-suffix"?