Renderer: Floating `:` at returns and raises with no `name` when `table_style: description-list`

[signekb]

When using table_style: description-list in _quarto.yml and returns and raises don't have names, their sections are still rendered with a : annotation separator (anno_sep). This results in a floating :.

Example of issue

From Shiny for Python

Expected behaviour

In this case, I would expect that there would be no colon and it would look like this:

## Returns
`Context`
A `~shiny.reactive.Context` class.

Raises
`RuntimeError`
If called outside of a reactive context.