Fix url of ulinks to point to mate-user-guide

Author: rbuj

help/C/index.docbook

@@ -479,9 +479,9 @@
         <title>Browsing the Filesystem</title>
         <para>Several &app; dialogs (<guilabel>New</guilabel>, <guilabel>Open</guilabel>, <guilabel>Extract</guilabel>,...) enable you
         to browse files and folders on your computer. Refer to the <ulink type="help" 
-        url="help:user-guide?filechooser-open">Desktop User Guide</ulink> to learn more about using the 
+        url="help:mate-user-guide/filechooser-open">Desktop User Guide</ulink> to learn more about using the 
         file browsing dialogs.</para>
-        <para>You can also refer to the <ulink type="help" url="help:user-guide?caja-bookmarks">Bookmarks 
+        <para>You can also refer to the <ulink type="help" url="help:mate-user-guide/caja-bookmarks">Bookmarks 
         section</ulink> of the Desktop User Guide to learn how you can use the <guilabel>Places</guilabel> pane 
         to access your favorite locations.</para>
      </sect3>