update webfigher reference app docs

mkt/ecosystem/templates/ecosystem/reference_apps/webfighter.html

@@ -37,7 +37,8 @@
       down an alien bug and destroy it. As a side-scrolling shooter, pick up
       various weapons to blast your way through enemies. In addition to
       destroying the alien bug, kill as many enemies as possible to get the
-      highest score.
+      highest score. 
+      <a href="https://marketplace.firefox.com/app/webfighter">View on the marketplace</a>
       <a href="{{ walkthrough_link }}"
          class="walkthrough">Read the full developer walkthrough</a>
     {% endtrans %}
@@ -64,6 +65,15 @@
           {% endtrans %}
         </p>
       </li>
+      <li>
+        {{ web_api('in_app_payments') }}
+        <p>
+          {% trans %}
+            The player can purchase items in a store that will aid their quest.
+            This shows the workflow for in-app payments.
+          {% endtrans %}
+        </p>
+      </li>
     </ul>
   </section>
 {% endblock %}

mkt/ecosystem/views.py

@@ -556,6 +556,10 @@ def apps_documentation(request, page=None):
         'fullscreen': {
             'link': '//developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode',
             'title': 'Fullscreen'
+        },
+        'in_app_payments': {
+            'link': '//developer.mozilla.org/en-US/docs/Web/Apps/Publishing/In-app_payments',
+            'title': 'In-app Payments'
         }
     }