Function render 

fn render(
    path: &Path,
    contents: &str,
    version: &str,
    date: &str,
    entry: &Entry,
) -> Result<String, MissingUnreleased>

Render a release entry above the current Unreleased content, which moves under the new version heading. The commits of entry follow that content, grouped by type. Its dependency updates are listed under Changed.

Errors

Returns an error when the changelog has no Unreleased heading.