Flow objects for online display

• vertical-scroll
• link
• marginalia
• multi-mode

(element note
  (make multi-mode
    multi-modes: '(#f expand)
    (make marginalia
      marginalia-side: 'start
      (make character
        font-name: "UNREGISTERED::SGML Open//Font::Icons"
        glyph-id: "UNREGISTERED::SGML Open//Glyph::Light bulb icon"))
    (make vertical-scroll
      label: 'expand
      (make paragraph))))