Sections example in PageHeader documentation is not correct

[Michal Predotka]

Go to: https://developer.ubuntu.com/api/apps/qml/sdk-15.04.4/Ubuntu.Components.PageHeader/
Look at how to use "extension"
There's an example code how to use Sections in PageHeader:

PageHeader {
    title: "Header with sections"
    extension: Sections {
        anchors {
            left: parent.left
            leftMargin: units.gu(2)
            bottom: parent.bottom
        }
        model: ["one", "two", "three"]
    }
}

Using that code leads to wrong look and behaviour of Sections component in an app. The Sections will be shifted to right by units.gu(2) and will not scroll if there's a lot of elements in Sections' model.
The correct code should be something like this:

 PageHeader {
    title: "Header with sections"
    extension: Sections {
        anchors {
            left: parent.left
            right: parent.right
            bottom: parent.bottom
        }
        model: ["one", "two", "three"]
    }
}