node ../../bin/texts.js --from json --to text
<<<
["text",
  ["heading", { "level": -3 },
    ["plain", "Heading"]
  ],
  ["heading", { "level": -2 },
    ["plain", "Subheading"]
  ],
  ["heading", { "level": -1 },
    ["plain", "Subsubheading"]
  ]
]
>>>
Heading
=======

Subheading
----------

### Subsubheading