ComposerPostPreview component renders Markdown as HTML using the
TextFormatter library, polling a data source for changes every 50ms. This is
done to prevent expensive redraws on e.g. every single keystroke, while
still retaining the perception of live updates for the user.
composer The state of the composer controlling this preview.
className A CSS class for the element surrounding the preview.
surround A callback that can execute code before and after re-render, e.g. for scroll anchoring.