Add a description to labels

This allows us to:

• describe what kind of issues should go in this label
• mention its specialists

It would also be really nice to show this description at the top of the issue list when it's filtered by a single label, for example at https://gitlab.com/gitlab-org/gitlab-ce/issues?label_name=Frontend.

We could show the same row as we do on https://gitlab.com/gitlab-org/gitlab-ce/labels, with the label on the left, description next to that, and N open issues on the right. With https://gitlab.com/gitlab-org/gitlab-ce/issues/12743 and https://gitlab.com/gitlab-org/gitlab-ce/issues/13501 it would also gain a Subscribe button and N open merge requests. We can leave off the Edit and Delete buttons.

cc @JobV

Milestone changed to 8.6

Interesting /cc @dzaporozhets

mentioned in merge request !2854 (merged)

@DouweM It seems that !2854 (merged) addressed this issue fully, though the auto close pattern wasn't used. Could you verify and close if necessary?

Status changed to closed