fix: make sure sapper crawls nofications/mentions (#1191)

src/routes/_pages/community/index.html

@@ -90,7 +90,6 @@
     <a href="/federated">Federated</a>
     <a href="/favorites">Favorites</a>
     <a href="/direct">Conversations</a>
-    <a href="/notifications/mentions">Notification mentions</a>
   </div>
 {/if}
 <style>

src/routes/_pages/notifications/index.html

@@ -8,6 +8,10 @@
 
     <p>Your notifications will appear here when logged in.</p>
   </FreeTextLayout>
+  <div style="display: none">
+    <!-- TODO: this is just a hack so that `sapper export` knows to crawl these files -->
+    <a href="/notifications/mentions">Notification mentions</a>
+  </div>
 </HiddenFromSSR>
 {/if}
 <script>