Bug report

I'm following the readme, and in my code I have the following:

Sass:

@use "@material/ripple";

.ripple {
    @include ripple.surface;
    @include ripple.radius-bounded;
    @include ripple.states;

    overflow: hidden; // Seems I need this?
}

JavaScript:

element.classList.add("ripple");
MDCRipple.attachTo(element);

No errors are produced, but it doesn't work.
When inspecting the compiled css, I see this line:

animation: mdc-ripple-fg-radius-in ...

However, no @keyframes have been emitted.

So, either there is a bug, or the readme forgot to mention something critical? :-)