Support 2nd level navigation keyboard shortcuts
Issue idea came from: https://gitlab.com/gitlab-org/gitlab-ce/issues/26348#note_23937925
Problem
With the move from #26348 (closed) with certain top level nav moving to 2nd level, they will currently loose their keyboard shorts. The modal to see which shortcuts there are, press ?
.
Proposal + Value
We should support 2nd level navigation keyboard shortcuts as well, as this fixes the kind of regression that was caused by https://gitlab.com/gitlab-org/gitlab-ce/issues/26348#note_23937925 and empowers power users better.