Slack apps can now use drop-down menus

Apps that integrate with Slack can now include drop-down menus in the messages that they post to the service, as part of a push to improve the interactivity of third-party integrations.Slack's message menus let apps spawn clickable lists that users can choose from in order to take actions that developers have enabled. For example, using menus would allow users to pick a from a list of customers in a CRM system that integrates with Slack, assuming the developers have built their service