Improved Custom Domain flow

Adding a custom domain was a bit confusing and buggy for some users. We have now improved it and made it more user-friendly.

• A new Custom domain section in the settings menu
• A new demo video guide to help you through the process
• Improved the UI for adding new domain
• The required DNS records menu has been improved to make it easy to copy values and more visible what to copy
• Our refresh button now also purge the cache to remove most issues with a not found error page
• Job board urls are now visible in the home page
• The custom domain section in the homepage was moved to the settings menu in a standalone section