Fixed tutorial links, especially to external pages
diff --git a/templates/doc/api/koralquery.html.ep b/templates/doc/api/koralquery.html.ep
index 4795573..d29bc94 100644
--- a/templates/doc/api/koralquery.html.ep
+++ b/templates/doc/api/koralquery.html.ep
@@ -4,4 +4,4 @@
 
 <p><strong>Main developer:</strong> Nils Diewald, Joachim Bingel</p>
 
-<p>The specification for KoralQuery is available on <a href="http://korap.github.io/Koral">GitHub</a>.</p>
+<p>The specification for KoralQuery is available on <%= doc_ext_link_to 'GitHub', "http://korap.github.io/Koral" %>.</p>