Update Slack links to include both invite and direct channel URLs#1787

Copilot wants to merge 1 commit intomastercert-manager/website:masterfrom

copilot/fix-e8391af4-4814-4439-ad18-d8b644d48e38cert-manager/website:copilot/fix-e8391af4-4814-4439-ad18-d8b644d48e38Copy head branch name to clipboard