Update datagrid.md

Make the binding use Items

docs/controls/datagrid.md

@@ -37,7 +37,7 @@ This will generate a DataGrid with column header names. FirstName and LastName.
         x:Class="AvaloniaAppTemplate.MainWindow"
         Title="AvaloniaAppTemplate">
     <Grid>
-        <DataGrid Name="MyDataGrid" ItemsSource="{Binding People}" >
+        <DataGrid Name="MyDataGrid" Items="{Binding People}" >
         </DataGrid>
     </Grid>
 </Window>
@@ -64,7 +64,7 @@ The DataGrid uses the same class Person as before, but now with custom column he
         x:Class="AvaloniaAppTemplate.MainWindow"
         Title="AvaloniaAppTemplate">
     <Grid>
-        <DataGrid Name="MyDataGrid" ItemsSource="{Binding People}" AutoGenerateColumns="False" >
+        <DataGrid Name="MyDataGrid" Items="{Binding People}" AutoGenerateColumns="False" >
             <DataGrid.Columns>
                 <DataGridTextColumn Header="Forename"  Binding="{Binding FirstName}"/>
                 <DataGridTextColumn Header="Surname" Binding="{Binding LastName}" />
@@ -82,4 +82,4 @@ The DataGrid uses the same class Person as before, but now with custom column he
 | `Items` | Gets or sets a collection that is used to generate the content of the control. |
 | `CanUserReorderColumns` |Indicates whether the user can change the column display order by dragging column headers with the mouse. |
 | `CanUserResizeColumns` | Indicates whether the user can adjust column widths using the mouse. |
-| `CanUserSortColumns` | Indicates whether the user can sort columns by clicking the column header. |
+| `CanUserSortColumns` | Indicates whether the user can sort columns by clicking the column header. |