Update index

README.txt

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-
 100 Numpy exercices
 ===================
 

index.rst

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 100 numpy exercises
 ===================
 
--------------------------------------
 A joint effort of the numpy community
 -------------------------------------
 
+The goal is both to offer a quick reference for new and old users and to
+provide also a set of exercices for those who teach.
+
+If you remember having asked or answered a (short) problem, you can send a pull
+request. The format is:
+
+
+#. Find indices of non-zero elements from [1,2,0,0,4,0]
+
+   .. code:: python
+
+      # Author: Somebody
+
+      print np.nonzero([1,2,0,0,4,0])
+
+
+If you can provide the assumed level of the answer, that would be even better.
+
+Here is what the page looks like so far:
+
+http://www.loria.fr/~rougier/teaching/numpy.100/index.html
+
+(The level names came from an old-game: Dungeon Master)
+
+
+
 .. contents::
    :local:
    :depth: 1