Multiline comment breaks Prometheus format

[Fabian Schmengler />]

If activating `magento_cronjob_broken_count', Prometheus cannot parse these lines:

# HELP magento_cronjob_broken_count_total Magento 2 CronJob Broken Count. 
Broken CronJobs occur when when status is pending but execution_time is set.

For multiline help texts, we should probably add # before each line

[Fabian Schmengler />]

Resolved by #11 (did not see that one)

[David Lambauer]

Thanks for reporting this Fabian! Merged the PR.