Fix the sample home page

Ooui/Anchor.cs

@@ -18,5 +18,18 @@ namespace Ooui
             : base ("a")
         {
         }
+
+        public Anchor (string href)
+            : this ()
+        {
+            HRef = href;
+        }
+
+        public Anchor (string href, string text)
+            : this ()
+        {
+            HRef = href;
+            Text = text;
+        }
     }
 }

PlatformSamples/AspNetCoreMvc/Views/Shared/_Layout.cshtml

@@ -41,7 +41,7 @@
         <hr />
         <footer>
             <p>&copy; 2017 - @DateTime.UtcNow.Year Frank A. Krueger</p>
-            @{ var e = new Ooui.Sa.Button("Hello World"); }
+            @{ var e = new Ooui.Anchor ("https://github.com/praeclarum/Ooui", "π"); }
             <ooui element="e" />
             <!--Html.Ooui (e)-->
         </footer>