Docs for SystemHooks should explain how they differ for ordinary WebHooks
What
Add description to https://docs.gitlab.com/ce/system_hooks/system_hooks.html
Why
I wasn't sure of the difference between SystemHooks and WebHooks and couldn't tell from the code. The docs didn't make it clear either, but from the api docs I eventually deduced that these must be instance wide rather then project specific.
Todo
Add a sentence clarifying that system hooks are applied instance-wide by a GitLab sysadmin.
Edited by Achilleas Pipinellis