Hello Will,
There are a few operations you can do on a chat message, but I am afraid that you cannot edit the like after it was sent to the other party. You can delete the message from your chat window, but that will not delete it from the other party's window. You can also create a permalink to the chat string or tag it, for easy search.
Adding links to a chat string sent some time in the past is not possible, but we'll create a story in our roadmap out of this idea and see if other people find it useful.
Thank you!
