The original LibHTML commit makes it sound like it was originally intended for embedding, so I don't see why not: https://github.com/SerenityOS/serenity/commit/a67e823838943b.... Electron has affordances beyond just being a web view, so you would have to add those (or work around not having them).
My question as a systems programming newbie:
Could a compiled binary of this project with HTML and CSS be used to create cross platform apps like Electron?