when the section parser encountered blockquote>p structure it was ignoring the blockquote and creating plain markup sections
adds special handling for blockquote>p so that the intention of blockquote semantics is not lost when a blockquote contains one or more paragraphs of quoted content
closes https://github.com/bustle/mobiledoc-kit/issues/715
blockquote>pstructure it was ignoring the blockquote and creating plain markup sectionsblockquote>pso that the intention of blockquote semantics is not lost when a blockquote contains one or more paragraphs of quoted content