Add IRC and switch2osm to help page, slight language improvement

app/views/site/help.html.erb

@@ -4,7 +4,7 @@
 
 <p class='introduction'><%= t "help_page.introduction" %></p>
 
-<% ['welcome', 'beginners_guide', 'help', 'mailing_lists', 'forums', 'wiki'].each do |site| %>
+<% ['welcome', 'beginners_guide', 'help', 'mailing_lists', 'forums', 'irc', 'switch2osm', 'wiki'].each do |site| %>
   <% unless site == 'welcome' && !@user %>
   <div class='<%= site %> help-item'>
   <h3>

config/locales/en.yml

@@ -1167,7 +1167,15 @@ en:
     forums:
       url: http://forum.openstreetmap.org/
       title: Forums
-      description: The same as above for those that prefer a bulletin board style interface.
+      description: Questions and discussions for those that prefer a bulletin board style interface.
+    irc:
+      url: http://irc.openstreetmap.org/
+      title: IRC
+      description: Interactive chat in many different languages and on many topics.
+    switch2osm:
+      url: https://switch2osm.org/
+      title: switch2osm
+      description: Help for companies and organisations switching to OpenStreetMap based maps and other services.
     wiki:
       url: http://wiki.openstreetmap.org/
       title: wiki.openstreetmap.org