[JIRA] (OVIRT-496) Add documentation for oVirt gerrit hooks

Add documentation for oVirt gerrit hooks ---------------------------------------- Key: OVIRT-496 URL: https://ovirt-jira.atlassian.net/browse/OVIRT-496 Project: oVirt - virtualization made easy Issue Type: Task Reporter: eyal edri [Administrator] Assignee: dcaro Priority: High We are missing documentation for all the Gerrit hooks and their configuration. Please add a page to the official infra docs page with information on all the hooks. It should include: * relevant code/repos * list of active hooks and their purpose * location of conf files, meaning of each config option * troubleshooting