chore(docs): add message hub client example #995

Job	Run time
dco / check	2s
reuse / test	8s
e2e-test / e2e-test	4m 39s
warmup-caches / build	52s
multi-platform / windows-latest / test	5m 35s
test / coverage	1m 43s
check / clippy	39s
test / test	47s
check / fmt	24s
check / doc	36s
check / stable / for-publish	1m 40s
check / minimal-versions	59s
check / features	3m 34s
check / msrv / 1.78	29s
check / semver	-1s
	22m 6s

Provide feedback