Show popover on summary comment help icon instead of linking to docs
To avoid having users navigate away from their current task, to go to the docs, let's add a popover that appears when hovering the question mark icon, per https://design.gitlab.com/usability/helping-users/#help-icon
If that's not possible and space is tight, use the help icon that, when hovered or focused on, shows the summary in a popover. The popover title should be the question that is answered by the summary. A “Learn more” link can be added to the popover to associate additional, relevant information.
