Add Blaxamarin sample AboutPage

Uses new Label.FormattedText support

samples/BlaxamarinSample/About.razor

@@ -0,0 +1,65 @@
+@using Xamarin.Essentials
+
+<StackLayout>
+    <StackLayout Orientation="StackOrientation.Horizontal">
+        @*<ContentView Padding="0,40,0,40" VerticalOptions="FillAndExpand">
+            <Image Source="xamarin_logo.png" VerticalOptions="Center" HeightRequest="64" />
+        </ContentView>*@
+    </StackLayout>
+</StackLayout>
+<ScrollView>
+    <StackLayout Orientation="StackOrientation.Vertical">
+        <Label FontSize="22">
+            <FormattedText>
+                <FormattedString>
+                    <Spans>
+                        <Span Text="AppName" FontAttributes="FontAttributes.Bold" FontSize="22" />
+                        <Span Text=" " />
+                        <Span Text="1.0" ForegroundColor="@lightTextColor" />
+                    </Spans>
+                </FormattedString>
+            </FormattedText>
+        </Label>
+        <Label>
+            <FormattedText>
+                <FormattedString>
+                    <Spans>
+                        <Span Text="This app is written in C# and native APIs using the" />
+                        <Span Text=" " />
+                        <Span Text="Xamarin Platform" FontAttributes="FontAttributes.Bold" />
+                        <Span Text="." />
+                    </Spans>
+                </FormattedString>
+            </FormattedText>
+        </Label>
+        <Label>
+            <FormattedText>
+                <FormattedString>
+                    <Spans>
+                        <Span Text="It shares code with its" />
+                        <Span Text=" " />
+                        <Span Text="iOS, Android, and Windows" FontAttributes="FontAttributes.Bold" />
+                        <Span Text=" " />
+                        <Span Text="versions." />
+                    </Spans>
+                </FormattedString>
+            </FormattedText>
+        </Label>
+        <Button Text="Learn more"
+                OnClick="@OpenWeb"
+                BackgroundColor="@primaryColor"
+                TextColor="Color.White" />
+    </StackLayout>
+</ScrollView>
+
+@code
+{
+    Color primaryColor = Color.FromHex("2196F3");
+    Color accentColor = Color.FromHex("96d1ff");
+    Color lightTextColor = Color.FromHex("999999");
+
+    async Task OpenWeb()
+    {
+        await Launcher.OpenAsync(new Uri("https://xamarin.com/platform"));
+    }
+}

samples/BlaxamarinSample/TodoApp.razor

@@ -8,4 +8,8 @@
     <ContentPage Title="Counter">
         <Counter />
     </ContentPage>
+    <ContentPage Title="About">
+        <About />
+    </ContentPage>
 </TabbedPage>
+