add promotion tab

PCUT/PCUT/Pages/MainMenuPage.xaml

@@ -71,6 +71,18 @@
                         Background= "{ThemeResource SystemAccentColor}" 
                         Margin="0,0,3,0"/>
 
+                    <NavigationViewItem 
+                        x:Name= "PromotionNavItem" 
+                        Content="Promotion"
+                        Tag= "Promotion"
+                        CornerRadius= "10"
+                        Background= "{ThemeResource SystemAccentColor}" 
+                        Margin="0,0,3,0">
+                        <NavigationViewItem.Icon>
+                            <BitmapIcon UriSource="ms-appx:///Assets/PromotionIcon.png" />
+                        </NavigationViewItem.Icon>
+                    </NavigationViewItem>
+
                     <NavigationViewItem 
                         x:Name= "AdminCenterNavItem" 
                         Icon="Admin" Content="Admin" 

PCUT/PCUT/Pages/Promotion/Promotion.xaml

@@ -0,0 +1,14 @@
+<Page
+    x:Class="PCUT.Pages.Promotion.Promotion"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:PCUT.Pages.Promotion"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+
+    <Grid>
+        <WebView Source="https://pcut.vn/dai-ly" />
+    </Grid>
+</Page>

PCUT/PCUT/Pages/Promotion/Promotion.xaml.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+
+// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=234238
+
+namespace PCUT.Pages.Promotion
+{
+    /// <summary>
+    /// An empty page that can be used on its own or navigated to within a Frame.
+    /// </summary>
+    public sealed partial class Promotion : Page
+    {
+        public Promotion()
+        {
+            this.InitializeComponent();
+        }
+    }
+}