Added a way to open url from the selection into the browser

MainPage.xaml

@@ -4,7 +4,7 @@
              xmlns:hackerNews="clr-namespace:HackerNews"
              x:Class="HackerNews.MainPage"
              x:DataType="hackerNews:NewsViewModel">
-   <ListView x:Name="NewsListView">
+   <ListView x:Name="NewsListView" ItemSelected="NewsListView_OnItemSelected">
        <ListView.ItemTemplate>
            <DataTemplate>
                <TextCell x:DataType="hackerNews:StoryModel"

MainPage.xaml.cs

@@ -15,4 +15,21 @@ protected override async void OnAppearing()
         base.OnAppearing();
         await _newsViewModel.Refresh();
     }
+
+    private async void NewsListView_OnItemSelected(object sender, SelectedItemChangedEventArgs e)
+    {
+        var listView = (ListView)sender;
+        listView.SelectedItem = null;
+
+        if (e.SelectedItem is not StoryModel storyModel) return;
+        if (!string.IsNullOrEmpty(storyModel.Url))
+        {
+            var browserOptions = new BrowserLaunchOptions();
+            await Browser.Default.OpenAsync(storyModel.Url, browserOptions);
+        }
+        else
+        {
+            await DisplayAlert("Invalid Article", "ASK HN articles have no url", "OK");
+        }
+    }
 }