I'm working on a prototype that's basically made for what you're trying to do. A text command based UX tool. You can create both text-renderings and image-renderings: https://medium.com/proof-of-concept/creating-a-true-ux-tool-...

I wrote a number of articles on it, and soon will open up an online version of the prototype. Love to get your feedback.

Similar, but for MOTD on linux/unix boxes