extended intro example

docs/index.rst

@@ -20,9 +20,13 @@ In short, dataset combines the straightforwardness of NoSQL interfaces with the
 
    import dataset
 
-   db = dataset.connect('sqlite:///database.db')
-   db['sometable'].insert(dict(name='John Doe', age=37))
-   db['sometable'].insert(dict(name='Jane Doe', age=34, gender='female'))
+   db = dataset.connect('sqlite:///:memory:')
+
+   table = db['sometable']
+   table.insert(dict(name='John Doe', age=37))
+   table.insert(dict(name='Jane Doe', age=34, gender='female'))
+
+   john = table.find_one(name='John Doe')
 
 
 Here is `similar code, without dataset <https://gist.github.com/gka/5296492>`_.