Documentation on $SYS/broker/mqtt/# topics is wrong

(AI-free text)

https://mosquitto.org/man/mosquitto-8.html lists various topics like $SYS/broker/mqtt/connect/received in the section "Broker Status". These are never published, as of version 2.1.2.

In sys_tree.c, these topics are excluded explicitly from being published. The associated commit states

Not published in $SYS, may be made available for plugins.

So, the documentation is incorrect. I suggest to remove the unavailable topics.