Bug 1226420 - Add a message about using github to file addons.mozilla.org bugs

Author: dklawren

extensions/BMO/template/en/default/bug/create/custom_forms.none.tmpl

@@ -16,6 +16,12 @@
 
 [%
 custom_forms = {
+  "addons.mozilla.org" => [
+    {
+      link  => "https://github.com/mozilla/addons/issues",
+      title => "Report an issue with addons.mozilla.org on GitHub."
+    }
+  ],
   "mozilla.org" => [
     {
       link  => "form.moz.project.review",