Animate details in normalize.css

[argyleink]

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

also add animated details

@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 #512 (comment)