make buttons pop a bit more

src/Microsoft.Tye.Hosting/Dashboard/Shared/MainLayout.razor

@@ -7,10 +7,10 @@
 <div class="main">
     <div class="top-row">
         <div class="top-nav-item nav-item px-1">
-            <a href="https://aka.ms/AA7q20u" target="_blank">Tell us what you think!</a>
+            <a href="https://aka.ms/AA7q20u" target="_blank" class="bg-secondary">Tell us what you think!</a>
         </div>
-        <div class="top-nav-item nav-item px-1">
+        <div class="top-nav-item nav-item px-1 ">
-            <a href="https://github.com/dotnet/tye" target="_blank">About</a>
+            <a href="https://github.com/dotnet/tye" target="_blank" class="bg-secondary">About</a>
         </div>
     </div>