Benchmark quarkus/spring integration properties must be documented

These docs:
https://www.optaplanner.org/docs/optaplanner/latest/integration/integration.html#integrationWithQuarkus
https://www.optaplanner.org/docs/optaplanner/latest/integration/integration.html#integrationWithSpringBoot

don't cover all the properties, namely the benchmarker ones.

Use the same docs as in the javadocs of those properties, if desirable.