tableOfContents :: Pandoc -> Pandoc
tableOfContents doc =
  let headers = query collectHeaders doc
  in walk (generateTOC headers) doc
tableOfContents :: Pandoc -> Pandoc
tableOfContents doc =
  let headers = query collectHeaders doc
  in walk (generateTOC headers) doc
tableOfContents doc =
  let headers = query collectHeaders doc
  in walk (generateTOC headers) doc