Not detecting anything when serde(flatten) is used

[nyurik]

Modify the README example with these instead, and nothing gets detected.

#[derive(Debug, PartialEq, Deserialize)]
struct Package {
    #[serde(flatten)]
    pub sub: SubPackage,
}

#[derive(Debug, PartialEq, Deserialize)]
struct SubPackage {
    name: String,
    dependencies: Map<String, Dependency>,
}