I know that I can parse and render an HTML document with Kramdown in ruby using something like

```
require 'kramdown'

s = 'This is a _document_'
Kramdown::Document.new(s).to_html
# '<p>This is a <i>document</i></p>'

```

In this case, the string `s` may contain a full document in markdown syntax.

What I want to do, however, is to parse `s` assuming that it only contains span-level markdown syntax, and obtain the rendered html. In particular there should be no `<p>`, `<blockquote>`, or, e.g., `<table>` in the rendered html.

```
s = 'This is **only** a span-level string'
# .. ??? ...
# 'This is <b>only</b> a span-level string'

```

How can I do this?