I have a working installation of 8.9.6 Gitlab + Mattermost. When I paste urls to Wikipedia and YouTube into Mattermost, I see the link previews. However, when I link to Gitlab commits or issues, I don’t see any preview. Also, I’m assuming there is a short-hand for referring to issues, commits, diffs, etc. from Gitlab in Mattermost. How can I achieve gitlab link previews and what short-hand syntax is available?