Preserve inline-level formatting when rewriting text

[mkremins]

When rewriting a block of text into a chunk of poetry, we currently disregard inline-level formatting (such as italics and bolded text) entirely. Human-generated blackout poetry, on the other hand, often makes use of formatting in the underlying text to interesting aesthetic effect.

Perhaps we could take steps to preserve inline-level text formatting in the generated poetry by keeping track of where inline-level HTML tags (such as <em> and <strong>) open and close in the source text, then reinserting these tags in the proper places when writing out the poemified HTML.