Enhance documentation and add BackgroundColor property

This commit introduces additional XML documentation comments for the `DoughnutChartDataset` class and its properties, including links to relevant Chart.js documentation for border alignment and border radius. A new `BackgroundColor` property is added to the `DoughnutChartDatasetData` record, allowing for background color customization. The `Circumference` property has been updated with comments related to clipping and documentation links. Various annotations such as `[AddedVersion("1.0.0")]`, `[DefaultValue(...)]`, and `[Description(...)]` have been added to improve overall documentation and usability.

NOTE: This commit message is auto-generated using GitHub Copilot.

Author: gvreddy04

BlazorExpress.ChartJS/Models/ChartDataset/DoughnutChart/DoughnutChartDataset.cs

@@ -29,6 +29,7 @@ public class DoughnutChartDataset : ChartDataset<double?>
     /// <para>
     /// Default value is 'center'.
     /// </para>
+    /// <see href="https://www.chartjs.org/docs/latest/charts/doughnut.html#border-alignment" />
     /// </summary>
     [AddedVersion("1.0.0")]
     [DefaultValue("center")]
@@ -94,6 +95,7 @@ public class DoughnutChartDataset : ChartDataset<double?>
     /// <para>
     /// Default value is 0.
     /// </para>
+    /// <see href="https://www.chartjs.org/docs/latest/charts/doughnut.html#border-radius" />
     /// </summary>
     [AddedVersion("1.0.0")]
     [DefaultValue(0)]
@@ -128,6 +130,9 @@ public class DoughnutChartDataset : ChartDataset<double?>
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public double? Circumference { get; set; }
 
+    //Clip
+    //https://www.chartjs.org/docs/latest/charts/doughnut.html#general
+
     [AddedVersion("1.0.0")]
     [DefaultValue("new()")]
     [Description("")]

BlazorExpress.ChartJS/Models/ChartDataset/DoughnutChart/DoughnutChartDatasetData.cs

@@ -13,6 +13,13 @@ public DoughnutChartDatasetData(string? datasetLabel, double data, string? backg
 
     #region Properties, Indexers
 
+    /// <summary>
+    /// Gets or initializes the background color as a string.
+    /// </summary>
+    [AddedVersion("1.0.0")]
+    [DefaultValue(null)]
+    [Description("")]
+    [ParameterTypeName("string?")]
     public string? BackgroundColor { get; init; }
 
     #endregion