One thing I would really appreciate in this repository (and many like it) would be a simple, short, snippet of code that shows a typical use case of whatever the repo is selling me. Life's too short to dig around in the guts of the repository to find stuff like this out, it should be front and center. I want to know about the ergonomics and hackability of what I'm about to delve into.
You are looking for the marketing page not the GitHub page then: https://messageformat.unicode.org/