Fix: Export PDF produces different HTML than Export HTML. #384

[lightrabbit]

This issue #384 is caused by the fact that cheerio automatically adds closing tags for unclosed opening tags. However, when processing HTML fragments with html_block, the input HTML may not always be a complete document.

This leads to situations where:

<div><img src="...">
# some title
some text
</div>

is processed into:

<div><img src="..."></div>
# some title
some text
// Here, the </div> is automatically removed by cheerio.

The issue arises because cheerio assumes that any unclosed tags should be properly closed, which can cause unexpected behavior when working with incomplete HTML fragments.