Usage

@display.TableOfContents(display.TOCProps{
    Title: "On this page",   // default "On this page"
    Items: []display.TOCItem{
        {Label: "Introduction", Href: "#intro",   Level: 1},
        {Label: "Installation",  Href: "#install", Level: 2},  // indented
        {Label: "Usage",         Href: "#usage",   Level: 1,
            Children: []display.TOCItem{
                {Label: "Basic", Href: "#basic", Level: 2},
            },
        },
    },
})