doc(tutorial): correct a dead link.

c5180365 · François Ferry · f050428ae7b2 · 761df97f
Commit c5180365 authored Dec 14, 2020 by François Ferry
--- a/doc/tutorials/base/conclusion.rst
+++ b/doc/tutorials/base/conclusion.rst
@@ -15,4 +15,4 @@ into view writing and interface customisation... Yet a lot of fun stuff to
 discover! You will find more `tutorials and howtos`_ in the blog published on the
 CubicWeb.org website.

-.. _`tutorials and howtos`: ../../tutorials
+.. _`tutorials and howtos`: ../../tutorials/index.html