[Collapsible] Implement Collapsible

[danilo-leal]

API

// JSX
<Collapsible.Root defaultOpen={false}>  // or `open` for controlled mode
  <Collapsible.Trigger className="MyCollapsible-trigger">
    Trigger
  </Collapsible.Trigger>
  
  <Collapsible.Content className="MyCollapsible-content">
    This the collapsed content
  </Collapsible.Content>
</Accordion.Root>

// HTML
<button
  type="button"
  aria-controls="ContentId"
  aria-expanded="false"
  class="MyCollapsible-trigger"
>
  Trigger
</button>

<div class="MyCollapsible-content" id="ContentId" hidden="hidden">
  This the collapsed content
</div>

[mj12albert]

Bumping this to work on together with #25