Where do you at R7 get the little icons for workflows that use Slack? e.g. Workflow Started
And paste it at will in your artifacts. If you google Unicode emoji you can get a ton of stuff to use.
You can also use the :emoji_name: format for Slack! This works for standard emojis, like
:rocket:, and for custom emojis you (or others) add to your Slack workspace, like :megaman:
I get all mine from here: