Update README.md

Addressed the concerns

Author: SreemonPremkumarM

README.md

@@ -7,33 +7,22 @@ This sample shows how to programmatically expand an item in [WPF TreeView](https
 #### XAML
 
 ``` csharp
-public MainWindow()
-{
-    InitializeComponent();
-    TreeViewAdv treeViewAdv = new TreeViewAdv();
-    TreeViewItemAdv root1 = new TreeViewItemAdv() { Header = "Marital Status" };
-    TreeViewItemAdv subitem11 = new TreeViewItemAdv() { Header = "Single" };
-    TreeViewItemAdv subitem12 = new TreeViewItemAdv() { Header = "Married" };
-    TreeViewItemAdv subitem13 = new TreeViewItemAdv() { Header = "Married with Children" };
-    root1.Items.Add(subitem11);
-    root1.Items.Add(subitem12);
-    root1.Items.Add(subitem13);
-    TreeViewItemAdv root2 = new TreeViewItemAdv() { Header = "Baby Vaccines" };
-    TreeViewItemAdv subitem21 = new TreeViewItemAdv() { Header = "Hepatitis B" };
-    TreeViewItemAdv subitem22 = new TreeViewItemAdv() { Header = "Tetanus" };
-    TreeViewItemAdv subitem23 = new TreeViewItemAdv() { Header = "Polio" };
-    TreeViewItemAdv subitem24 = new TreeViewItemAdv() { Header = "Measles" };
-    root2.Items.Add(subitem21);
-    root2.Items.Add(subitem22);
-    root2.Items.Add(subitem23);
-    root2.Items.Add(subitem24);
-    TreeViewItemAdv root3 = new TreeViewItemAdv() { Header = "Baby Vaccines" };
-    treeViewAdv.Items.Add(root1);
-    treeViewAdv.Items.Add(root2);
-    treeViewAdv.Items.Add(root3);
-    Grid.Children.Add(treeViewAdv);
-    root1.IsExpanded = true;
-}
+<Grid x:Name="Grid">
+    <syncfusion:TreeViewAdv Name="treeViewAdv">
+        <syncfusion:TreeViewItemAdv Name="treeViewItemAdv" Header="Marital Status">
+            <syncfusion:TreeViewItemAdv Header="Single"/>
+            <syncfusion:TreeViewItemAdv Header="Married"/>
+            <syncfusion:TreeViewItemAdv Header="Married with Children"/>
+        </syncfusion:TreeViewItemAdv>
+        <syncfusion:TreeViewItemAdv Header="Baby Vaccines">
+            <syncfusion:TreeViewItemAdv Header="Hepatitis B"/>
+            <syncfusion:TreeViewItemAdv Header="Tetanus"/>
+            <syncfusion:TreeViewItemAdv Header="Polio"/>
+            <syncfusion:TreeViewItemAdv Header="Measles"/>
+        </syncfusion:TreeViewItemAdv>
+        <syncfusion:TreeViewItemAdv Header="Country Information"/>
+    </syncfusion:TreeViewAdv>
+</Grid>
 ```
 
 #### C#
@@ -47,18 +36,22 @@ public MainWindow()
     TreeViewItemAdv subitem11 = new TreeViewItemAdv() { Header = "Single" };
     TreeViewItemAdv subitem12 = new TreeViewItemAdv() { Header = "Married" };
     TreeViewItemAdv subitem13 = new TreeViewItemAdv() { Header = "Married with Children" };
+
     root1.Items.Add(subitem11);
     root1.Items.Add(subitem12);
     root1.Items.Add(subitem13);
+
     TreeViewItemAdv root2 = new TreeViewItemAdv() { Header = "Baby Vaccines" };
     TreeViewItemAdv subitem21 = new TreeViewItemAdv() { Header = "Hepatitis B" };
     TreeViewItemAdv subitem22 = new TreeViewItemAdv() { Header = "Tetanus" };
     TreeViewItemAdv subitem23 = new TreeViewItemAdv() { Header = "Polio" };
     TreeViewItemAdv subitem24 = new TreeViewItemAdv() { Header = "Measles" };
+
     root2.Items.Add(subitem21);
     root2.Items.Add(subitem22);
     root2.Items.Add(subitem23);
     root2.Items.Add(subitem24);
+
     TreeViewItemAdv root3 = new TreeViewItemAdv() { Header = "Baby Vaccines" };
     treeViewAdv.Items.Add(root1);
     treeViewAdv.Items.Add(root2);
@@ -78,18 +71,22 @@ Public Sub New()
     Dim subitem11 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Single"}
     Dim subitem12 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Married"}
     Dim subitem13 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Married with Children"}
+
     root1.Items.Add(subitem11)
     root1.Items.Add(subitem12)
     root1.Items.Add(subitem13)
+
     Dim root2 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Baby Vaccines"}
     Dim subitem21 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Hepatitis B"}
     Dim subitem22 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Tetanus"}
     Dim subitem23 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Polio"}
     Dim subitem24 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Measles"}
+
     root2.Items.Add(subitem21)
     root2.Items.Add(subitem22)
     root2.Items.Add(subitem23)
     root2.Items.Add(subitem24)
+
     Dim root3 As TreeViewItemAdv = New TreeViewItemAdv() With {.Header = "Baby Vaccines"}
     treeViewAdv.Items.Add(root1)
     treeViewAdv.Items.Add(root2)
@@ -99,4 +96,4 @@ Public Sub New()
 End Sub
 ```
 
-![TreeView with expanded nodes](TreeViewWithExpandedNodes.png)
+![TreeView with expanded nodes](TreeViewWithExpandedNodes.png)