Walk every line of the Markdown source and return the first line that
survives shouldSkipDescriptionLine. Inline Markdown decorations
are stripped and the result is truncated to fit <meta description>.
Parameters
markdown: string
Markdown source
Returns string
Prose description, or empty string when nothing qualifies
Walk every line of the Markdown source and return the first line that survives shouldSkipDescriptionLine. Inline Markdown decorations are stripped and the result is truncated to fit
<meta description>.