Limit to expose code rendered in slack

[rpandyaArlo]

Is your feature request related to a problem? Please describe. Due to security & compliance, we want to limit code to be exposed to Slack. We want only limited information to be sent to Slack related to PR like a reporter, assignees, reviewers, PR number & title, and comments.

Describe the solution you'd like Option to limit payload sent to Slack.

[flavigneseedbox]

We might have to ban it because we don't want code accidentally posted because of a link preview.