docs: fix github docs link (#14787)
docs: fix github docs link (#14787)

The `https://help.github.com/send-pull-requests/` is not active anymore, it's better ti use this one `https://docs.github.com/en/github/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request-from-a-fork` and event is more suitable for this particular case.
graetzer/arangodb,wiltonlazary/arangodb,graetzer/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,graetzer/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,graetzer/arangodb,arangodb/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,wiltonlazary/arangodb,graetzer/arangodb,arangodb/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,arangodb/arangodb,arangodb/arangodb,graetzer/arangodb,wiltonlazary/arangodb,arangodb/arangodb,arangodb/arangodb,wiltonlazary/arangodb,arangodb/arangodb,arangodb/arangodb