pub fn get_stable_version(manifest: &DocsManifest) -> (String, VersionManifest) {
    let mut stable: Option<(String, VersionManifest)> = None;
    for (name, details) in manifest.iter() {
        if details.state == VersionState::Stable {
            stable = Some((name.clone(), details.clone()));
            break;
        }
    }
    if let Some(stable) = stable {
        stable
    } else {
        panic!("no stable version set for docs");
    }
}
Gets the latest stable version of the docs from the given manifest. This
returns the version's name and metadata.
website/src/templates/docs/generation.rs