Success! Final stack:
  [(Lean.Doc.Syntax.para
    "para{"
    [(Lean.Doc.Syntax.link
      "["
      [(Lean.Doc.Syntax.text (str "\"My link\""))]
      "]"
      (Lean.Doc.Syntax.ref
       "["
       (str "\"lean\"")
       "]"))]
    "}")
   (Lean.Doc.Syntax.link_ref
    "["
    (str "\"lean\"")
    "]:"
    (str "\"https://lean-lang.org\""))
   (Lean.Doc.Syntax.para
    "para{"
    [(Lean.Doc.Syntax.text (str "\"hello\""))]
    "}")]
All input consumed.