* Details component
* polish arrow animation
* fix text selection bug
* fix some edge cases + polish
* example of overriding baseClassName
* Move Details component to theme-common
* make component work even when JS is disabled or failed to load
* update arrow transform
* Details component: better handling of no-JS fallback mode: avoid delaying arrow navigation when JS (see review)
* prefix css vars with --docusaurus
* improve css arrow styling
* slightly change details/summary design
* better md doc + include quotes and details in doc
