Add ubuntu-fr wiki with new doku engine

searx/settings.yml

 #    number_of_results : 5
 #    timeout : 3.0
 
+  - name : ubuntuwiki
+    engine : doku
+    shortcut : uw
+    base_url : 'http://doc.ubuntu-fr.org'
+
 locales:
     en : English
     bg : Български (Bulgarian)