Added loading message

Signed-off-by: Marcus Noble <github@marcusnoble.co.uk>

templates/index.html

@@ -55,6 +55,7 @@
     <h1>Next Book</h1>
     <p>Suggestions for the next book to read from your Storygraph to-read pile</p>
   </header>
+  {{ if index . "Fiction" }}
     <main>
       {{ $cat := "Fiction" }}
       {{ $book := index . $cat }}
@@ -101,5 +102,10 @@
         </div>
       {{ end }}
     </main>
+  {{ else }}
+    <div class="container" style="text-align: center;padding: 4rem;">
+      <h2>Still loading book recommendations...</h2>
+    </div>
+  {{ end }}
 </body>
 </html>