How to show list with section in SwiftUI

Issue #511

struct CountriesView: View {
    let groups: [Group]

    init(countries: [Country]) {
        self.groups = CountryManager.shared.groups(countries: countries)
    }

    var body: some View {
        List {
            ForEach(groups) { group in
                Section(
                    header:
                        Text(group.initial)
                            .foregroundColor(Color.yellow)
                            .styleTitle(),
                    content: {
                        ForEach(group.countries) { country in
                            CountryRow(country: country)
                        }
                    }
                )
            }
        }
    }
}