Add base URL to Mediawiki Hubot extension

Fixes #5

site-cookbooks/kosmos-mediawiki/recipes/default.rb

@@ -112,7 +112,8 @@ webhook_token = hal8000_freenode_data_bag_item['webhook_token']
 template "#{node['mediawiki']['webdir']}/extensions/MediawikiHubot/DefaultConfig.php" do
   source "MediawikiHubot/DefaultConfig.php.erb"
   variables webhook_url: "http://localhost:8080/incoming/#{webhook_token}",
-            room_name: "#kosmos"
+            room_name: "#kosmos",
+            wiki_url: "https://wiki.kosmos.org/"
 end
 
 ruby_block "configuration" do

site-cookbooks/kosmos-mediawiki/templates/default/MediawikiHubot/DefaultConfig.php.erb

@@ -27,7 +27,7 @@ if (!isset($hpc_attached)) die();
 ##################
   // REQUIRED
   // URL of your MediaWiki installation incl. the trailing /.
-  $wgWikiUrl       = "";
+  $wgWikiUrl       = "<%= @wiki_url %>";
   // Wiki script name. Leave this to default one if you do not have URL rewriting enabled.
   $wgWikiUrlEnding = "index.php?title=";
   // OPTIONAL