Alerting: Clarify PagerDuty integrationKey format (#62463)
**What is this feature?**
Simply a documentation update.
**Why do we need this feature?**
Clarify the doc, so people don't waste time integrating the wrong key,
e.g. #8979, #9036, https://community.librenms.org/t/19013
**Who is this feature for?**
Developers doing a PagerDuty integration.
(cherry picked from commit a7c4872bcd)
Co-authored-by: Andre Miras <AndreMiras@users.noreply.github.com>
Grot (@grafanabot)
c567e690ad