Add example of new rank sort extensions

examples/Demo/Shared/Pages/DataGrid/DataGridPage.razor

@@ -65,6 +65,14 @@
     </Description>
 </DemoSection>
 
+<DemoSection Title="SortBy Rank" Component="@typeof(DataGridRankSort)">
+    <Description>
+        <p>
+            Here is an example that demonstrates the rank sort.
+        </p>
+    </Description>
+</DemoSection>
+
 
 <DemoSection Title="Remote data" Component="@typeof(DataGridRemoteData)">
     <Description>

examples/Demo/Shared/Pages/DataGrid/Examples/DataGridRankSort.razor

@@ -0,0 +1,43 @@
+<FluentDataGrid Items="@_gridData" ResizableColumns=true GridTemplateColumns="0.5fr 0.5fr">
+    <PropertyColumn Sortable="true" Property="x => x.Number" Title="Number" />
+
+    <TemplateColumn Sortable="true" SortBy="groupRank" Title="Group">
+        @context.Group
+    </TemplateColumn>
+
+</FluentDataGrid>
+
+<p>Keep numbers always sorted ascending inside the group when sorting by group</p>
+<FluentDataGrid Items="@_gridData" ResizableColumns=true GridTemplateColumns="0.5fr 0.5fr">
+    <PropertyColumn Sortable="true" Property="x => x.Number" Title="Number" />
+
+    <TemplateColumn Sortable="true" SortBy="groupRankNumberAlwaysAscending" Title="Group">
+        @context.Group
+    </TemplateColumn>
+
+</FluentDataGrid>
+
+
+
+@code {
+    GridSort<GridRow> groupRank = GridSort<GridRow>
+            .ByAscending(x => x.Group)
+            .ThenAscending(x => x.Number);
+
+    GridSort<GridRow> groupRankNumberAlwaysAscending = GridSort<GridRow>
+        .ByAscending(x => x.Group)
+        .ThenAlwaysAscending(x => x.Number);
+
+    private static readonly IQueryable<GridRow> _gridData = new GridRow[] {
+        new(2, "B"),
+        new(1, "A"),
+        new(4, "B"),
+        new(3, "A")
+    }.AsQueryable();
+
+    public class GridRow(int number, string group)
+    {
+        public int Number { get; } = number;
+        public string Group { get; } = group;
+    }
+}