Usage

@display.DonutChart(display.DonutChartProps{
    Title:     "9.4k",     // center top label (defaults to formatted total)
    Subtitle:  "Total",    // center bottom label
    Size:      200,        // SVG width & height in px (default 200)
    Thickness: 40,         // ring thickness in px (default 40)
    Slices: []display.DonutSlice{
        {Label: "Organic",  Value: 4200, Color: "#3b82f6"},
        {Label: "Direct",   Value: 2800, Color: "#10b981"},
        {Label: "Referral", Value: 1500, Color: "#f59e0b"},
    },
})