Add links to the Beginners' guide, mailing lists and forums to the help page

From a pure design and content view (where the content is factual) a link
to learnosm.org would really be better. Potentially learnosm could be forked
and a version hosted on OSMF infrastructure with the marketing verbiage
for HOTs view of the world removed.

app/views/site/help.html.erb

@@ -4,7 +4,7 @@
 
 <p class='introduction'><%= t "help_page.introduction" %></p>
 
-<% ['welcome', 'help', 'wiki'].each do |site| %>
+<% ['welcome', 'beginners_guide', 'help', 'mailing_lists', 'forums', 'wiki'].each do |site| %>
   <% unless site == 'welcome' && !@user %>
   <div class='<%= site %> help-item'>
   <h3>