Animate details in normalize.css

https://developer.chrome.com/docs/css-ui/animate-to-height-auto/

also add animated details
```css
@supports (interpolate-size: allow-keywords) {
:root {
interpolate-size: allow-keywords;
}

details {
transition: height 0.5s ease;
height: 2.5rem;

&[open] {
height: auto;
overflow: clip; /* Clip off contents while animating */
}
}
}
```

_Originally posted by @argyleink in https://github.com/argyleink/open-props/issues/512#issuecomment-2361864293_

Inspect normalize.css and compare the requested details animation with the linked Chrome guidance. Confirm how the supplied @supports block should fit the stylesheet, then verify that details elements animate when opened without affecting unsupported browsers.

Written by the indexing model from the issue text.