Remove entire page content from Slack wiki edit notifications

Currently, in at least up to 10.3.6, Slack notifications for wiki page edits include the entire changed wiki page in them. This is a lot of content and uninteresting for any nontrivial page. There's already the link to the page included for people who want to view it. (Much more interesting would be information what actually changed, but I suppose that's not doable at the moment as the UI doesn't offer possibility to diff wiki page revisions).

So, please remove page content from Slack wiki edit notifications. (And similarly also for other wiki change notifications, unless they're already included in them, haven't checked.)