A paragraph (Lexical type "paragraph").
text_format and text_style are the format and the style that Lexical
gives to new text in the paragraph.
Blank lines
An empty paragraph between other blocks (of the root, of a quote of
blocks or of a footnote) is a blank line, as a person typed it. It keeps
its height in HTML (<p><br></p>), and it is in Markdown, which
Kotoba.Content.from_markdown/2 reads back as an empty paragraph. An
empty paragraph at the start or the end is not a blank line.
The blank_lines: :collapse render option leaves blank lines out of the
HTML, the text and the Markdown.
Summary
Functions
Returns true when the paragraph has no content: no children, or only
text nodes with no text.