Updated README file

Author: macagua

README.rst

@@ -5,6 +5,14 @@ Polls
 Polls is a simple Django app to conduct Web-based polls. For each
 question, visitors can choose between a fixed number of answers.
 
+.. figure:: https://raw.github.com/macagua/django192-tutorial/reusable-apps/docs/screenshot.png
+  :align: center
+  :height: 431px
+  :width: 362px
+  :alt: The Django app to conduct Web-based polls.
+
+  The Django app to conduct Web-based polls.
+
 Detailed documentation is in the "docs" directory.
 
 Quick start
@@ -26,4 +34,4 @@ Quick start
 4. Start the development server and visit http://127.0.0.1:8000/admin/
    to create a poll (you'll need the Admin app enabled).
 
-5. Visit http://127.0.0.1:8000/polls/ to participate in the poll.
+5. Visit http://127.0.0.1:8000/polls/ to participate in the poll.