Sync notifications and troubleshooting guides (#998)

* Add help articles

* Broadcast sync messages as notifications

* Lint fixes

* more lint fixes

* Remove redundant code

app/controllers/help/articles_controller.rb

@@ -0,0 +1,11 @@
+class Help::ArticlesController < ApplicationController
+  layout "with_sidebar"
+
+  def show
+    @article = Help::Article.find(params[:id])
+
+    unless @article
+      head :not_found
+    end
+  end
+end