add note about examples to head of parallel docs

docs/source/parallel/parallel_demos.txt

@@ -1,3 +1,5 b''
+.. _parallel_examples:
+
 =================
 Parallel examples
 =================

docs/source/parallel/parallel_intro.txt

@@ -4,6 +4,17 b''
 Overview and getting started
 ============================
 
+
+Examples
+========
+
+We have various example scripts and notebooks for using IPython.parallel in our
+:file:`docs/examples/parallel` directory, or they can be found `on GitHub`__.
+Some of these are covered in more detail in the :ref:`examples
+<parallel_examples>` section.
+
+.. __: https://github.com/ipython/ipython/tree/master/docs/examples/parallel
+
 Introduction
 ============