Shorter link previews

[driesvints]

Is your feature request related to a problem? Please describe. Although it's nice that we get some details about an issue/pr when the link preview is shown, more often it's pretty disruptive that your entire chat window gets filled with it and it's hard to follow along with a convo.

Describe the solution you'd like I wouldn't go as far as https://github.com/integrations/slack/issues/487 but what would be cool is if you could disable the issue/pr body while still maintaining all the other info. That or shorten it to about three lines or so.

Describe alternatives you've considered No real alternatives are available other than totally disabling the integration.

Additional context Here's a screenshot of where a link to an issue gets unfurled. It takes up the entire screen.