API
Earmark.as_html
{:ok, html_doc, []} = Earmark.as_html(markdown)
{:ok, html_doc, deprecation_messages} = Earmark.as_html(markdown)
{:error, html_doc, error_messages} = Earmark.as_html(markdown)
Earmark.as_html!
html_doc = Earmark.as_html!(markdown, options)
All messages are printed to stderr.