Add Dr. Dobbs article to docs

doc/index.rst

@@ -38,6 +38,9 @@ source distribution.)
 Tutorials
 =========
 
+* Gaston Hillar's `two-part article series
+  <http://www.drdobbs.com/open-source/easy-opencl-with-python/240162614>`_
+  in Dr. Dobb's Journal provides a friendly introduction to PyOpenCL.
 * `Simon McIntosh-Smith <http://www.cs.bris.ac.uk/~simonm/>`_
   and `Tom Deakin <http://www.tomdeakin.com/>`_'s course
   `Hands-on OpenCL <http://handsonopencl.github.io/>`_ contains